The Experts below are selected from a list of 32271 Experts worldwide ranked by ideXlab platform
Lawrence S. Chan - One of the best experts on this subject based on the ideXlab platform.
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the progression of inflammation parallels the dermal angiogenesis in a Keratin 14 il 4 transgenic model of atopic dermatitis
Microcirculation, 2008Co-Authors: L Chen, Deborah Marble, Rania Agha, Jennifer D Peterson, Robert P Becker, Tianquan Jin, Lawrence S. ChanAbstract:The role angiogenesis plays in atopic dermatitis is not well understood. The authors previously demonstrated ultrastructurally dermal microvascular angiogenesis in the IL-4-transgenic mouse model of atopic dermatitis. Here, they determine the angiogenic factors involved in dermal microvascular angiogenesis, regulatory function of inflammatory cytokines on the VEGF-A production, and microvascular permeability in this model. Computer-assisted photometric analyses for immunofluorescence-labeled CD31 demonstrated a progressive increase in blood vessel number, diameter, and percent dermal areas occupied by CD31(+) vessels as the disease evolves in transgenic mice from before disease onset through early and late skin lesions. Similar findings were documented for VEGR2(+) vessels. Quantification of skin angiogenic factor mRNAs showed progressive increase of transcripts of VEGF-A, but not VEGF-B, VEGF-C, or VEGF-D. ELISA showed a similar increase of VEGF-A in the serum and skin of transgenic mice. IL-6 and IFN-gamma stimulated VEGF-A mRNA production in the skin and in primary Keratinocytes of transgenic mice. Other skin angiogenic factors that increased included Ang-1, Ang-2, GBP-1, and VE-cadherin. Microvascular leakage began in the transgenic mouse skin before disease onset and peaked in the late stage. In conclusion, IL-6 and IFN-gamma may play important roles in upregulation of VEGF-A, along with other pro-angiogenic factors, to induce dermal microvascular angiogenesis.
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CCL27 is a critical factor for the development of atopic dermatitis in the Keratin-14 IL-4 transgenic mouse model
International immunology, 2006Co-Authors: L Chen, S Lin, Rania Agha-majzoub, Lutgart Overbergh, Chantal Mathieu, Lawrence S. ChanAbstract:The Keratin-14 IL-4 transgenic (Tg) mouse model of atopic dermatitis (AD) is characterized by skin infiltration of T cells, early up-regulation of Th2 cytokines and late surge of Th1 cytokines. In the present study, we investigated the role of CCL27, a T cell skin-homing chemokine known to be elevated in sera of human AD patients, in disease development in our animal model of AD. The results showed that the mRNA and protein levels of CCL27 in the skin and serum were significantly increased in IL-4 Tg mice. The percentage of T cells expressing CCR10 in skin draining lymph nodes of IL-4 Tg mice was increased, consistent with the findings of >80% of skin-infiltrating T cells in Tg mice expressing CCR10. Chemotaxis transmigration assay demonstrated that CCL27 promotes a greater degree of migration of T cells in diseased Tg mice. Subcutaneous injection of neutralizing anti-CCL27 to IL-4 Tg mice with early skin lesions resulted in reduced clinical progression of inflammation, accompanied with decreased T cell and mast cell infiltration in the skin, and down-regulation of inflammatory cytokines. In conclusion, CCL27 and CCR10 interaction is important for the development of skin inflammation in our AD model.
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the disease progression in the Keratin 14 il 4 transgenic mouse model of atopic dermatitis parallels the up regulation of b cell activation molecules proliferation and surface and serum ige
Clinical and Experimental Immunology, 2005Co-Authors: L Chen, Lutgart Overbergh, Chantal Mathieu, Sx Lin, Lawrence S. ChanAbstract:We have previously characterized the Keratin 14 interleukin-4-transgenic (IL-4-Tg) mouse model of atopic dermatitis as a chronic pruritic inflammatory skin disease typified by skin infiltration of inflammatory cells and early up-regulation of Th2 cytokines and late surge of Th1 cytokines. In the present study, we examined the involvement of B cells. Systematic examinations of the following immunological parameters on B cells were carried out in non-Tg control mice and in IL-4-Tg mice at before disease onset and early and late disease stages so that we could determine the immunological sequence of events leading to the disease development: surface expressions of IA/IE, activation and costimulatory molecules, proliferation under LPS or IgM stimulation, quantification of cell surface and serum IgE, IgG1, and IgG2a. Our results showed that as the disease progresses from before onset to early disease and to late disease, there is a parallel increase in surface markers of B cell activation (IA/IE, CD44, CD69, CD80 and CD86), in B cell proliferation, and in cell surface and serum IgE. Significant increases of Th2-driven serum IgG1 and IgE in early disease was followed by significant increase of Th1-driven IgG2a in late disease. Importantly the significant increases of activation molecule (IA/IE), proliferation (to LPS), and surface IgE on B cells of the IL-4-Tg mice precedes the up-regulation of serum IgE and disease onset. These data suggest that activated B cells may play a role in atopic dermatitis disease development by up-regulating serum IgE concentration, which serves as a marker of disease onset.
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angiogenesis the major abnormality of the Keratin 14 il 4 transgenic mouse model of atopic dermatitis
Microcirculation, 2005Co-Authors: Rania Aghamajzoub, Robert P Becker, Dean E Schraufnagel, Lawrence S. ChanAbstract:Objective: Angiogenesis plays an important role in psoriasis, but its role in atopic dermatitis is unknown. The authors examined the dermal microvasculature of an IL-4 transgenic mouse model of atopic dermatitis to determine whether angiogenesis was present.Methods: Transmission and scanning electron microscopy and confocal microscopy studies were performed.Results: Transmission electron microscopy showed sprouting, transcapillary pillars of intussusception, thickened endothelial cells with large nuclei, and increased interendothelial junctional cleft number and length. Compared to nontransgenic littermates, there was a significant increase in the lengths and numbers of the interendothelial junctional clefts, along with a decrease in the length ratios of tight junction to interendothelial junctional clefts in both the early and late disease stages. In the early and late skin lesions, scanning electron microscopy of vascular corrosion casts showed disorganization of the capillary network hierarchy with inc...
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angiogenesis the major abnormality of the Keratin 14 il 4 transgenic mouse model of atopic dermatitis
Microcirculation, 2005Co-Authors: Rania Aghamajzoub, Robert P Becker, Dean E Schraufnagel, Lawrence S. ChanAbstract:Objective: Angiogenesis plays an important role in psoriasis, but its role in atopic dermatitis is unknown. The authors examined the dermal microvasculature of an IL-4 transgenic mouse model of ato...
Guy J Lyons - One of the best experts on this subject based on the ideXlab platform.
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visualizing the contribution of Keratin 14 limbal epithelial precursors in corneal wound healing
Stem cell reports, 2019Co-Authors: Mijeong Park, Alexander Richardson, Elvis Pandzic, Erwin P Lobo, Renee Whan, Stephanie L Watson, Guy J Lyons, Denis WakefieldAbstract:Summary It is thought that corneal epithelial injuries resolve by leading-edge cells “sliding” or “rolling” into the wound bed. Here, we challenge this notion and show by real-time imaging that corneal wounds initially heal by “basal cell migration.” The K14CreERT2-Confetti multi-colored reporter mouse was employed to spatially and temporally fate-map cellular behavior during corneal wound healing. Keratin-14+ basal epithelia are forced into the wound bed by increased population pressure gradient from the limbus to the wound edge. As the defect resolves, centripetally migrating epithelia decelerate and replication in the periphery is reduced. With time, Keratin-14+-derived clones diminish in number concomitant with their expansion, indicative that clonal evolution aligns with neutral drifting. These findings have important implications for the involvement of stem cells in acute tissue regeneration, in key sensory tissues such as the cornea.
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Visualizing the Contribution of Keratin-14+ Limbal Epithelial Precursors in Corneal Wound Healing
Elsevier, 2019Co-Authors: Mijeong Park, Alexander Richardson, Elvis Pandzic, Erwin P Lobo, Renee Whan, Stephanie L Watson, Guy J Lyons, Denis Wakefield, Nick Di GirolamoAbstract:Summary: It is thought that corneal epithelial injuries resolve by leading-edge cells “sliding” or “rolling” into the wound bed. Here, we challenge this notion and show by real-time imaging that corneal wounds initially heal by “basal cell migration.” The K14CreERT2-Confetti multi-colored reporter mouse was employed to spatially and temporally fate-map cellular behavior during corneal wound healing. Keratin-14+ basal epithelia are forced into the wound bed by increased population pressure gradient from the limbus to the wound edge. As the defect resolves, centripetally migrating epithelia decelerate and replication in the periphery is reduced. With time, Keratin-14+-derived clones diminish in number concomitant with their expansion, indicative that clonal evolution aligns with neutral drifting. These findings have important implications for the involvement of stem cells in acute tissue regeneration, in key sensory tissues such as the cornea. : In this article, Di Girolamo and colleagues visualized the contribution of K14+ limbal epithelial precursors in resolving corneal epithelial debridement wounds. They noted that population pressure from the limbal perimeter is the main driver of K14+ basal cell displacement during the initial phase of injury repair. Keywords: cornea wound healing, limbal epithelial stem cells, K14CreERT2-Confetti transgenic mice, basal cell migration, organ-culture system, spatiotemporal image correlation spectroscopy, computational modelin
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Keratin 14 positive precursor cells spawn a population of migratory corneal epithelia that maintain tissue mass throughout life
Stem cell reports, 2017Co-Authors: Alexander Richardson, Erwin P Lobo, Guy J Lyons, Denis Wakefield, Naomi C Delic, Mary R Myerscough, Nick Di GirolamoAbstract:Summary The dynamics of epithelial stem cells (SCs) that contribute to the formation and maintenance of the cornea are poorly understood. Here, we used K14CreER T2 -Confetti (Confetti) mice, sophisticated imaging, and computational modeling to trace the origins and fate of these cells during embryogenesis and adult life. We show that Keratin-14 (K14 + )-expressing progenitors are defined and widely distributed across the E16.5 cornea, after which they undergo cycles of proliferation and dispersal prior to eyelid opening. K14 + clonal patches disappear from the central cornea and are replaced by limbal-derived K14 + streaks, a finding that aligned with bromodeoxyuridine label-retaining studies. We also elucidated the mechanism by which SC clones are lost during life and propose this is due to population asymmetry and neutral drift. Finally, we established that the occurrence of an equatorial migratory mid-line is a consequence of apoptosis in a narrow nasal-temporal region, the site where eyelids meet during blinking.
Nick Di Girolamo - One of the best experts on this subject based on the ideXlab platform.
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inducing dry eye disease using a custom engineered desiccation system impact on the ocular surface including Keratin 14 positive limbal epithelial stem cells
Ocular Surface, 2021Co-Authors: Richard Zhang, Mijeong Park, Elvis Pandzic, Denis Wakefield, Nick Di GirolamoAbstract:Abstract Purpose Dry eye disease (DED) is characterized by loss of tear film stability that becomes self-sustaining in a vicious cycle of pathophysiological events. Currently, desiccation stress (DS) is the dominant procedure for inducing DED in mice, however its’ effect on limbal epithelial stem cells (LESCs) has been overlooked. This study aimed to establish a DS model via the use of a novel hardware to investigate the impact on the ocular surface including LESCs. Methods A mouse transporter unit was customized to generate a dehumidified environment. C57BL/6J mice were exposed to mild DS and injected with scopolamine hydrobromide (SH) or remained untreated (UT) under standard vivarium conditions for 10 consecutive days (n = 28/group). Clinical assessments included phenol red tear-thread test, fluorescein staining and optical coherence tomography assessments. Histopathological and immunofluorescence was used to evaluate tissue architecture, goblet cell (GC) status, lacrimal gland (LG) inflammation and epithelial phenotype on the ocular surface. Whole flat-mounted corneas were immunostained for Keratin-14 (K14), then imaged by confocal microscopy and analyzed computationally to investigate the effect of DS on LESCs. Results Custom modifications made to the animal transporter unit resulted in dehumidified cage relative humidity (RH) of 43.5 ± 4.79% compared to the vivarium 53.9 ± 1.8% (p = 0.0243). Under these conditions, aqueous tear production in mice was suppressed whilst corneal permeability and corneal irregularity significantly increased. H&E staining indicated stressed corneal basal epithelial cells and increased desquamation. DS-exposed mice had reduced GC density (41.0 ± 5.10 GC/mm vs 46.9 ± 3.88 GC/mm, p = 0.0482) and LGs from these mice exhibited elevated CD4+ cell infiltration compared to controls. DS elicited K14+ epithelial cell displacement, as indicated by increased fluorescence signal at a distance of 50–100 μm radially inwards from the limbus [0.63 ± 0.053% (DS) vs 0.54 ± 0.060% (UT), p = 0.0317]. Conclusions Application of mild DS using customized hardware and SH injections generated features of DED in mice. Following DS, ocular surface epithelial cell health decreased and LESCs appeared stressed. This suggested that potential downstream effects of DS on corneal homeostasis are present, a phenomenon that is currently under-investigated. The method used to induce DED in this study enables the development of a chronic model which more closely resembles disease seen in the clinic.
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Visualizing the Contribution of Keratin-14+ Limbal Epithelial Precursors in Corneal Wound Healing
Elsevier, 2019Co-Authors: Mijeong Park, Alexander Richardson, Elvis Pandzic, Erwin P Lobo, Renee Whan, Stephanie L Watson, Guy J Lyons, Denis Wakefield, Nick Di GirolamoAbstract:Summary: It is thought that corneal epithelial injuries resolve by leading-edge cells “sliding” or “rolling” into the wound bed. Here, we challenge this notion and show by real-time imaging that corneal wounds initially heal by “basal cell migration.” The K14CreERT2-Confetti multi-colored reporter mouse was employed to spatially and temporally fate-map cellular behavior during corneal wound healing. Keratin-14+ basal epithelia are forced into the wound bed by increased population pressure gradient from the limbus to the wound edge. As the defect resolves, centripetally migrating epithelia decelerate and replication in the periphery is reduced. With time, Keratin-14+-derived clones diminish in number concomitant with their expansion, indicative that clonal evolution aligns with neutral drifting. These findings have important implications for the involvement of stem cells in acute tissue regeneration, in key sensory tissues such as the cornea. : In this article, Di Girolamo and colleagues visualized the contribution of K14+ limbal epithelial precursors in resolving corneal epithelial debridement wounds. They noted that population pressure from the limbal perimeter is the main driver of K14+ basal cell displacement during the initial phase of injury repair. Keywords: cornea wound healing, limbal epithelial stem cells, K14CreERT2-Confetti transgenic mice, basal cell migration, organ-culture system, spatiotemporal image correlation spectroscopy, computational modelin
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Keratin 14 positive precursor cells spawn a population of migratory corneal epithelia that maintain tissue mass throughout life
Stem cell reports, 2017Co-Authors: Alexander Richardson, Erwin P Lobo, Guy J Lyons, Denis Wakefield, Naomi C Delic, Mary R Myerscough, Nick Di GirolamoAbstract:Summary The dynamics of epithelial stem cells (SCs) that contribute to the formation and maintenance of the cornea are poorly understood. Here, we used K14CreER T2 -Confetti (Confetti) mice, sophisticated imaging, and computational modeling to trace the origins and fate of these cells during embryogenesis and adult life. We show that Keratin-14 (K14 + )-expressing progenitors are defined and widely distributed across the E16.5 cornea, after which they undergo cycles of proliferation and dispersal prior to eyelid opening. K14 + clonal patches disappear from the central cornea and are replaced by limbal-derived K14 + streaks, a finding that aligned with bromodeoxyuridine label-retaining studies. We also elucidated the mechanism by which SC clones are lost during life and propose this is due to population asymmetry and neutral drift. Finally, we established that the occurrence of an equatorial migratory mid-line is a consequence of apoptosis in a narrow nasal-temporal region, the site where eyelids meet during blinking.
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Keratin 14 expression in epithelial progenitor cells of the developing human cornea
Stem Cells and Development, 2016Co-Authors: Yas Eghtedari, Alexander Richardson, Denis Wakefield, Kelly Mai, Benjamin Heng, Gilles J Guillemin, Nick Di GirolamoAbstract:A healthy and transparent cornea is essential for exquisite vision. During adulthood, its epithelium is constantly replenished through the activity of its stem cells (SCs). Precisely when these cells develop and their distribution across the ocular surface remain incompletely characterized in man. We postulated that the human fetal cornea harbors SCs that can be identified with Keratin (K) 14 and αv-integrin, two markers we and others previously used to identify their adult counterparts. Immunofluorescence, cell culture, quantitative real-time polymerase chain reaction (qRT-PCR), and colony-forming assays were performed on fetal and adult biomaterial to locate progenitors and establish their phenotypic and functional properties. K14 was used to map the spatiotemporal distribution of precursor cell activity across the developing cornea, divulging a dynamic pattern of vertical and horizontal consolidated expression with increasing gestational age. K14 was coexpressed with αv-integrin in fetal and adult corneas and cultured corneolimbal epithelium, and colony-forming efficiency (an indicator of SC activity) was similar in cells from both sources. Finally, fetal cells were adherent, grew well, and maintained a K14 phenotype on contact lenses, a substrate we previously used to deliver cells to patients with blinding corneal disease. This study provides valuable insights into the development of the cornea, including the formation of the SC repository, the distribution of these cells across the ocular surface, and a preliminary attempt at harnessing, phenotyping, and functionally characterizing these cells. Future studies will focus on isolating fetal SCs to determine their utility as an alternative cell therapy for patients suffering from corneal blindness.
Denis Wakefield - One of the best experts on this subject based on the ideXlab platform.
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inducing dry eye disease using a custom engineered desiccation system impact on the ocular surface including Keratin 14 positive limbal epithelial stem cells
Ocular Surface, 2021Co-Authors: Richard Zhang, Mijeong Park, Elvis Pandzic, Denis Wakefield, Nick Di GirolamoAbstract:Abstract Purpose Dry eye disease (DED) is characterized by loss of tear film stability that becomes self-sustaining in a vicious cycle of pathophysiological events. Currently, desiccation stress (DS) is the dominant procedure for inducing DED in mice, however its’ effect on limbal epithelial stem cells (LESCs) has been overlooked. This study aimed to establish a DS model via the use of a novel hardware to investigate the impact on the ocular surface including LESCs. Methods A mouse transporter unit was customized to generate a dehumidified environment. C57BL/6J mice were exposed to mild DS and injected with scopolamine hydrobromide (SH) or remained untreated (UT) under standard vivarium conditions for 10 consecutive days (n = 28/group). Clinical assessments included phenol red tear-thread test, fluorescein staining and optical coherence tomography assessments. Histopathological and immunofluorescence was used to evaluate tissue architecture, goblet cell (GC) status, lacrimal gland (LG) inflammation and epithelial phenotype on the ocular surface. Whole flat-mounted corneas were immunostained for Keratin-14 (K14), then imaged by confocal microscopy and analyzed computationally to investigate the effect of DS on LESCs. Results Custom modifications made to the animal transporter unit resulted in dehumidified cage relative humidity (RH) of 43.5 ± 4.79% compared to the vivarium 53.9 ± 1.8% (p = 0.0243). Under these conditions, aqueous tear production in mice was suppressed whilst corneal permeability and corneal irregularity significantly increased. H&E staining indicated stressed corneal basal epithelial cells and increased desquamation. DS-exposed mice had reduced GC density (41.0 ± 5.10 GC/mm vs 46.9 ± 3.88 GC/mm, p = 0.0482) and LGs from these mice exhibited elevated CD4+ cell infiltration compared to controls. DS elicited K14+ epithelial cell displacement, as indicated by increased fluorescence signal at a distance of 50–100 μm radially inwards from the limbus [0.63 ± 0.053% (DS) vs 0.54 ± 0.060% (UT), p = 0.0317]. Conclusions Application of mild DS using customized hardware and SH injections generated features of DED in mice. Following DS, ocular surface epithelial cell health decreased and LESCs appeared stressed. This suggested that potential downstream effects of DS on corneal homeostasis are present, a phenomenon that is currently under-investigated. The method used to induce DED in this study enables the development of a chronic model which more closely resembles disease seen in the clinic.
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visualizing the contribution of Keratin 14 limbal epithelial precursors in corneal wound healing
Stem cell reports, 2019Co-Authors: Mijeong Park, Alexander Richardson, Elvis Pandzic, Erwin P Lobo, Renee Whan, Stephanie L Watson, Guy J Lyons, Denis WakefieldAbstract:Summary It is thought that corneal epithelial injuries resolve by leading-edge cells “sliding” or “rolling” into the wound bed. Here, we challenge this notion and show by real-time imaging that corneal wounds initially heal by “basal cell migration.” The K14CreERT2-Confetti multi-colored reporter mouse was employed to spatially and temporally fate-map cellular behavior during corneal wound healing. Keratin-14+ basal epithelia are forced into the wound bed by increased population pressure gradient from the limbus to the wound edge. As the defect resolves, centripetally migrating epithelia decelerate and replication in the periphery is reduced. With time, Keratin-14+-derived clones diminish in number concomitant with their expansion, indicative that clonal evolution aligns with neutral drifting. These findings have important implications for the involvement of stem cells in acute tissue regeneration, in key sensory tissues such as the cornea.
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Visualizing the Contribution of Keratin-14+ Limbal Epithelial Precursors in Corneal Wound Healing
Elsevier, 2019Co-Authors: Mijeong Park, Alexander Richardson, Elvis Pandzic, Erwin P Lobo, Renee Whan, Stephanie L Watson, Guy J Lyons, Denis Wakefield, Nick Di GirolamoAbstract:Summary: It is thought that corneal epithelial injuries resolve by leading-edge cells “sliding” or “rolling” into the wound bed. Here, we challenge this notion and show by real-time imaging that corneal wounds initially heal by “basal cell migration.” The K14CreERT2-Confetti multi-colored reporter mouse was employed to spatially and temporally fate-map cellular behavior during corneal wound healing. Keratin-14+ basal epithelia are forced into the wound bed by increased population pressure gradient from the limbus to the wound edge. As the defect resolves, centripetally migrating epithelia decelerate and replication in the periphery is reduced. With time, Keratin-14+-derived clones diminish in number concomitant with their expansion, indicative that clonal evolution aligns with neutral drifting. These findings have important implications for the involvement of stem cells in acute tissue regeneration, in key sensory tissues such as the cornea. : In this article, Di Girolamo and colleagues visualized the contribution of K14+ limbal epithelial precursors in resolving corneal epithelial debridement wounds. They noted that population pressure from the limbal perimeter is the main driver of K14+ basal cell displacement during the initial phase of injury repair. Keywords: cornea wound healing, limbal epithelial stem cells, K14CreERT2-Confetti transgenic mice, basal cell migration, organ-culture system, spatiotemporal image correlation spectroscopy, computational modelin
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Keratin 14 positive precursor cells spawn a population of migratory corneal epithelia that maintain tissue mass throughout life
Stem cell reports, 2017Co-Authors: Alexander Richardson, Erwin P Lobo, Guy J Lyons, Denis Wakefield, Naomi C Delic, Mary R Myerscough, Nick Di GirolamoAbstract:Summary The dynamics of epithelial stem cells (SCs) that contribute to the formation and maintenance of the cornea are poorly understood. Here, we used K14CreER T2 -Confetti (Confetti) mice, sophisticated imaging, and computational modeling to trace the origins and fate of these cells during embryogenesis and adult life. We show that Keratin-14 (K14 + )-expressing progenitors are defined and widely distributed across the E16.5 cornea, after which they undergo cycles of proliferation and dispersal prior to eyelid opening. K14 + clonal patches disappear from the central cornea and are replaced by limbal-derived K14 + streaks, a finding that aligned with bromodeoxyuridine label-retaining studies. We also elucidated the mechanism by which SC clones are lost during life and propose this is due to population asymmetry and neutral drift. Finally, we established that the occurrence of an equatorial migratory mid-line is a consequence of apoptosis in a narrow nasal-temporal region, the site where eyelids meet during blinking.
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Keratin 14 expression in epithelial progenitor cells of the developing human cornea
Stem Cells and Development, 2016Co-Authors: Yas Eghtedari, Alexander Richardson, Denis Wakefield, Kelly Mai, Benjamin Heng, Gilles J Guillemin, Nick Di GirolamoAbstract:A healthy and transparent cornea is essential for exquisite vision. During adulthood, its epithelium is constantly replenished through the activity of its stem cells (SCs). Precisely when these cells develop and their distribution across the ocular surface remain incompletely characterized in man. We postulated that the human fetal cornea harbors SCs that can be identified with Keratin (K) 14 and αv-integrin, two markers we and others previously used to identify their adult counterparts. Immunofluorescence, cell culture, quantitative real-time polymerase chain reaction (qRT-PCR), and colony-forming assays were performed on fetal and adult biomaterial to locate progenitors and establish their phenotypic and functional properties. K14 was used to map the spatiotemporal distribution of precursor cell activity across the developing cornea, divulging a dynamic pattern of vertical and horizontal consolidated expression with increasing gestational age. K14 was coexpressed with αv-integrin in fetal and adult corneas and cultured corneolimbal epithelium, and colony-forming efficiency (an indicator of SC activity) was similar in cells from both sources. Finally, fetal cells were adherent, grew well, and maintained a K14 phenotype on contact lenses, a substrate we previously used to deliver cells to patients with blinding corneal disease. This study provides valuable insights into the development of the cornea, including the formation of the SC repository, the distribution of these cells across the ocular surface, and a preliminary attempt at harnessing, phenotyping, and functionally characterizing these cells. Future studies will focus on isolating fetal SCs to determine their utility as an alternative cell therapy for patients suffering from corneal blindness.
Dedee F Murrell - One of the best experts on this subject based on the ideXlab platform.
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epidermolysis bullosa simplex dowling meara due to an arginine to cysteine substitution in exon 1 of Keratin 14
Australasian Journal of Dermatology, 2002Co-Authors: Champi Premaratne, S Klingberg, Ian A Glass, Kellie Wright, Dedee F MurrellAbstract:Epidermolysis bullosa simplex (EBS) is a blistering disorder affecting the basal layer of the epidermis usually inherited in an autosomal dominant fashion. Most cases are caused by mutations in the genes encoding Keratin 5 (K5) and Keratin 14 (K14) and are characterized by cytolysis within the basal layer of the epidermis. We report a patient manifesting the Dowling-Meara variant of EBS in whom we characterized a cytosine to thymine transition at codon 125 (R125C) in K14. This missense mutation is located at the amino terminus of the helical rod domain of the Keratin 14 molecule, resulting in defective pairing with K5, thereby disrupting Keratin tonofibril integrity.
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Keratin 14 point mutations at codon 119 of helix 1a resulting in different epidermolysis bullosa simplex phenotypes
Journal of Investigative Dermatology, 2001Co-Authors: Rebecca E Cummins, S Klingberg, Dedee F Murrell, Julie Wesley, Maureen Rogers, Yali ZhaoAbstract:Epidermolysis bullosa simplex is a heterogeneous group of inherited bullous disorders due to mutations in Keratins 5 and 14. We report two different mutations in Keratin 14 at codon 119 of the helix initiation peptide, each with different phenotypic expression. One, a sporadic case that clinically resembles Dowling-Meara epidermolysis bullosa simplex, resulted from conversion of methionine to threonine (M119T). The other, a multigeneration family with the Koebner phenotype, resulted from a previously unreported methionine to valine substitution (M119V). We suggest that loss of hydrophobicity during conversion of methionine to threonine is responsible for the more severe presentation of the first family, whereas maintenance of the hydrophobic nature of the amino acid with conversion to valine resulted in a less severe variant of epidermolysis bullosa simplex. Although most prior mutations in the highly conserved boundary motif of the α-helix have resulted in the Dowling-Meara subtype, our findings confirm that it is not always possible to predict the epidermolysis bullosa simplex severity on the basis of the location of the mutation along the Keratin polypeptide. The specific amino acid substitution may be more critical in some cases.
