101
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Torbet J, Malbouyres M, Builles N, Justin V, Roulet M, Damour O, Oldberg A, Ruggiero F, Hulmes DJS. Orthogonal scaffold of magnetically aligned collagen lamellae for corneal stroma reconstruction. Biomaterials 2007; 28:4268-76. [PMID: 17618680 DOI: 10.1016/j.biomaterials.2007.05.024] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Accepted: 05/25/2007] [Indexed: 11/26/2022]
Abstract
The creation of 3D scaffolds that mimic the structure of physiological tissue required for normal cell function is a major bioengineering challenge. For corneal stroma reconstruction this necessitates the creation of a stroma-like scaffold consisting of a stack of orthogonally disposed sheets of aligned collagen fibrils. This study demonstrates that such a scaffold can be built up using magnetic alignment. By allowing neutralized acid-soluble type I collagen to gel in a horizontal magnetic field (7 T) and by combining a series of gelation-rotation-gelation cycles, a scaffold of orthogonal lamellae composed of aligned collagen fibrils has been formed. Although initially dilute, the gels can be concentrated without noticeable loss in orientation. The gels are translucent but their transparency can be greatly improved by the addition of proteoglycans to the gel-forming solution. Keratocytes align by contact guidance along the direction of collagen fibrils and respect the orthogonal design of the collagen template as they penetrate into the bulk of the 3D matrix. The scaffold is a significant step towards the creation of a corneal substitute with properties resembling those of native corneal stroma.
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Affiliation(s)
- Jim Torbet
- Institut de Biologie et Chimie des Protéines, CNRS UMR 5086, IFR 128 Biosciences Lyon-Gerland, 69367 Lyon, France.
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102
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Kothapalli KS, Anthony JC, Pan BS, Hsieh AT, Nathanielsz PW, Brenna JT. Differential cerebral cortex transcriptomes of baboon neonates consuming moderate and high docosahexaenoic acid formulas. PLoS One 2007; 2:e370. [PMID: 17426818 PMCID: PMC1847718 DOI: 10.1371/journal.pone.0000370] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Accepted: 03/20/2007] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (ARA, 20:4n-6) are the major long chain polyunsaturated fatty acids (LCPUFA) of the central nervous system (CNS). These nutrients are present in most infant formulas at modest levels, intended to support visual and neural development. There are no investigations in primates of the biological consequences of dietary DHA at levels above those present in formulas but within normal breastmilk levels. METHODS AND FINDINGS Twelve baboons were divided into three formula groups: Control, with no DHA-ARA; "L", LCPUFA, with 0.33%DHA-0.67%ARA; "L3", LCPUFA, with 1.00%DHA-0.67%ARA. All the samples are from the precentral gyrus of cerebral cortex brain regions. At 12 weeks of age, changes in gene expression were detected in 1,108 of 54,000 probe sets (2.05%), with most showing <2-fold change. Gene ontology analysis assigns them to diverse biological functions, notably lipid metabolism and transport, G-protein and signal transduction, development, visual perception, cytoskeleton, peptidases, stress response, transcription regulation, and 400 transcripts having no defined function. PLA2G6, a phospholipase recently associated with infantile neuroaxonal dystrophy, was downregulated in both LCPUFA groups. ELOVL5, a PUFA elongase, was the only LCPUFA biosynthetic enzyme that was differentially expressed. Mitochondrial fatty acid carrier, CPT2, was among several genes associated with mitochondrial fatty acid oxidation to be downregulated by high DHA, while the mitochondrial proton carrier, UCP2, was upregulated. TIMM8A, also known as deafness/dystonia peptide 1, was among several differentially expressed neural development genes. LUM and TIMP3, associated with corneal structure and age-related macular degeneration, respectively, were among visual perception genes influenced by LCPUFA. TIA1, a silencer of COX2 gene translation, is upregulated by high DHA. Ingenuity pathway analysis identified a highly significant nervous system network, with epidermal growth factor receptor (EGFR) as the outstanding interaction partner. CONCLUSIONS These data indicate that LCPUFA concentrations within the normal range of human breastmilk induce global changes in gene expression across a wide array of processes, in addition to changes in visual and neural function normally associated with formula LCPUFA.
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Affiliation(s)
- Kumar S.D. Kothapalli
- Division of Nutritional Sciences, Cornell University, Savage Hall, Ithaca, New York, United States of America
| | - Joshua C. Anthony
- Mead Johnson and Company, Evansville, Indiana, United States of America
| | - Bruce S. Pan
- Division of Nutritional Sciences, Cornell University, Savage Hall, Ithaca, New York, United States of America
| | - Andrea T. Hsieh
- Division of Nutritional Sciences, Cornell University, Savage Hall, Ithaca, New York, United States of America
| | - Peter W. Nathanielsz
- Center for Pregnancy and Newborn Research, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - J. Thomas Brenna
- Division of Nutritional Sciences, Cornell University, Savage Hall, Ithaca, New York, United States of America
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103
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Saika S, Shirai K, Yamanaka O, Miyazaki KI, Okada Y, Kitano A, Flanders KC, Kon S, Uede T, Kao WWY, Rittling SR, Denhardt DT, Ohnishi Y. Loss of osteopontin perturbs the epithelial-mesenchymal transition in an injured mouse lens epithelium. J Transl Med 2007; 87:130-8. [PMID: 17211411 DOI: 10.1038/labinvest.3700508] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
We previously reported that osteopontin (OPN), a matrix structural glycophosphoprotein, is upregulated in the injured mouse lens prior to the epithelial-mesenchymal transition (EMT). Here, we investigated the role of this protein in EMT of the lens epithelium during wound healing. The crystalline lens was injured by needle puncture in OPN-null (KO, n=40) and wild-type (WT, n=40) mice. The animals were killed at day 1, 2, 5, and 10 postinjury. Immunohistochemistry was employed to detect alpha-smooth muscle action (alphaSMA), a marker of EMT, collagen type I, transforming growth factor beta1 (TGFbeta1), TGFbeta2, and phospho-Smad2/3. Cell proliferation was assayed by examining uptake of bromodeoxyuridine (BrdU). The results showed that injury-induced EMT of mouse lens epithelium, as evaluated by histology, expression pattern of alphaSMA and collagen I, was altered in the absence of OPN with reduced phospho-Smad2/3 signaling. Upregulation of TGFbeta1 and TGFbeta2 in the epithelium was also inhibited. Cell proliferation was more active in KO mice as compared with WT mice at day 1 and 2, but not at day 5 and 10. An in vitro experiment shows OPN facilitates cell adhesion of lens epithelial cell line. OPN is required for activation of Smad2/3 signal in an injured lens epithelium and lens cell EMT.
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Affiliation(s)
- Shizuya Saika
- Department of Ophthalmology, Wakayama Medical University, Wakayama, Japan.
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104
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Abstract
Many transgenic and knockout mice exhibit pathogenic processes resembling human ocular surface diseases. Thus, the clinical manifestations of mouse lines can provide clues for identifying heritable human diseases of unknown etiology. However, mouse lines using conventional techniques of transgenesis and gene targeting often exhibit embryonic lethality and congenital defects, which preclude the use of such mouse models to study acquired ocular surface tissue diseases. These difficulties can be in part overcome by preparing mouse lines of inducible transgene expression, tissue-specific gene ablation, and inducible tissue-specific gene ablation. Conditional transgenic mouse lines live normally until administration of doxycycline and hormones that induce expression of the transgene and ablation of gene of interest. Toward this goal, we prepared 2 groups of genetically modified mouse lines: (1) transgenesis using keratocan promoter was used to create Kera-rtTA mice (doxycycline-inducible mice) and Cre-LoxP system (ie, Kera-Cre mice; conditional gene ablation in neural crest cell lineage and adult stromal keratocyte) and Kera-CrePR mice (RU-486 inducible); and (2) knock-in strategies were used to create Krt12-rtTA mice (doxycycline inducible), Krt12-Cre mice (conditional ablation in corneal epithelium), and Krt12rtTA-tet-O-Cre mice (doxycycline-inducible corneal epithelium-specific gene ablation). Using these mouse lines, we showed that transforming growth factor (TGF)-beta2 is essential for eye morphogenesis, TGF-alpha is a morphogen for eyelid formation, and lumican is a matrikine that has multiple regulatory functions on cell activities (eg, migration proliferation and gene expression) besides serving as a regulatory molecule of collagen fibrillogenesis. These mouse lines can also be used as models for development of therapeutic treatment regimens of ocular surface diseases using gene therapy and stem cell strategies.
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Affiliation(s)
- Winston W-Y Kao
- Department of Ophthalmology and Cell Biology, University of Cincinnati, 3225 Eden Avenue, Cincinnati, OH 45267, USA.
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105
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Chakravarti S, Zhang G, Chervoneva I, Roberts L, Birk DE. Collagen fibril assembly during postnatal development and dysfunctional regulation in the lumican-deficient murine cornea. Dev Dyn 2006; 235:2493-506. [PMID: 16786597 DOI: 10.1002/dvdy.20868] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The transparent cornea is the outer barrier of the eye and is its major refractive surface. Development of a functional cornea requires a postnatal maturation phase involving development, growth and organization of the stromal extracellular matrix. Lumican, a leucine-rich proteoglycan, is implicated in regulating assembly of collagen fibrils and the highly organized extracellular matrix essential for corneal transparency. We investigated the regulatory role(s) of lumican in fibril assembly during postnatal corneal development using wild type (Lum+/+) and lumican-null (Lum-/-) mice. In Lum+/+ mice, a regular architecture of small-diameter fibrils is achieved in the anterior stroma by postnatal day 10 (P10), while the posterior stroma takes longer to reach this developmental maturity. Thus, the anterior and the posterior stroma follow distinct developmental timelines and may be under different regulatory mechanisms. In Lum-/- mice, it is the posterior stroma where abnormal lateral associations of fibrils and thicker fibrils with irregular contours are evident as early as P10. In contrast, the anterior stroma is minimally perturbed by the absence of lumican. In Lum+/+ mice, lumican is expressed throughout the developing stroma at P10, with strong expression limited to the posterior stroma in the adult. Therefore, the posterior stroma, which is most vulnerable to lumican-deficiency, demonstrates an early developmental defect in fibril structure and architecture in the Lum-/- mouse. These defects underlie the reported increased light scattering and opacity detectable in the adult. Our findings emphasize the early regulation of collagen structure by lumican during postnatal development of the cornea.
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Affiliation(s)
- Shukti Chakravarti
- Department of Medicine, Johns Hopkins University Medical School, Baltimore, Maryland, USA
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106
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Khan AO, Aldahmesh M, Meyer B. Corneal ectasia and hydrops in a patient with autosomal recessive cornea plana. Ophthalmic Genet 2006; 27:99-101. [PMID: 17050286 DOI: 10.1080/13816810600862469] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
PURPOSE To report the development of corneal ectasia and hydrops in a patient with autosomal recessive cornea plana. METHODS Retrospective observational case report. RESULTS A 16-year-old male with a prior diagnosis of autosomal recessive cornea plana who complained of unilateral visual loss of one month's duration was found to have corneal edema consistent with resolving hydrops in the affected eye. The edema resolved over time, and keratometry revealed high astigmatism in both eyes despite documentation of no significant corneal astigmatism 11 years before. Slit-lamp examination confirmed corneal thinning in both eyes corresponding to the meridian of the astigmatism. The prior diagnosis of cornea plana was confirmed by molecular genetic testing. CONCLUSIONS Although not a characteristic finding of cornea plana, corneal ectasia can rarely occur and be associated with corneal hydrops.
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Affiliation(s)
- Arif O Khan
- Division of Pediatric Ophthalmology, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia.
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107
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Hayashida Y, Akama TO, Beecher N, Lewis P, Young RD, Meek KM, Kerr B, Hughes CE, Caterson B, Tanigami A, Nakayama J, Fukada MN, Tano Y, Nishida K, Quantock AJ. Matrix morphogenesis in cornea is mediated by the modification of keratan sulfate by GlcNAc 6-O-sulfotransferase. Proc Natl Acad Sci U S A 2006; 103:13333-8. [PMID: 16938851 PMCID: PMC1569164 DOI: 10.1073/pnas.0605441103] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Indexed: 11/18/2022] Open
Abstract
Matrix assembly and homeostasis in collagen-rich tissues are mediated by interactions with proteoglycans (PGs) substituted with sulfated glycosaminoglycans (GAGs). The major GAG in cornea is keratan sulfate (KS), which is N-linked to one of three PG core proteins. To ascertain the importance of the carbohydrate chain sulfation step in KS functionality, we generated a strain of mice with a targeted gene deletion in Chst5, which encodes an N-acetylglucosamine-6-O-sulfotransferase that is integral to the sulfation of KS chains. Corneas of homozygous mutants were significantly thinner than those of WT or heterozygous mice. They lacked high-sulfated KS, but contained the core protein of the major corneal KSPG, lumican. Histochemically stained KSPGs coassociated with fibrillar collagen in WT corneas, but were not identified in the Chst5-null tissue. Conversely, abnormally large chondroitin sulfate/dermatan sulfate PG complexes were abundant throughout the Chst5-deficient cornea, indicating an alteration of controlled PG production in the mutant cornea. The corneal stroma of the Chst5-null mouse exhibited widespread structural alterations in collagen fibrillar architecture, including decreased interfibrillar spacing and a more spatially disorganized collagen array. The enzymatic sulfation of KS GAG chains is thus identified as a key requirement for PG biosynthesis and collagen matrix organization.
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Affiliation(s)
- Yasutaka Hayashida
- *Department of Ophthalmology, Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Tomoya O. Akama
- Glycobiology Program, Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037
| | - Nicola Beecher
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Redwood Building, Cathays Park, Cardiff CF10 3NB, United Kingdom
| | - Philip Lewis
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Redwood Building, Cathays Park, Cardiff CF10 3NB, United Kingdom
| | - Robert D. Young
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Redwood Building, Cathays Park, Cardiff CF10 3NB, United Kingdom
| | - Keith M. Meek
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Redwood Building, Cathays Park, Cardiff CF10 3NB, United Kingdom
| | - Briedgeen Kerr
- Connective Tissue Biology Laboratory, School of Biosciences, Cardiff University, Museum Avenue, Cathays Park, Cardiff CF10 3US, United Kingdom
| | - Clare E. Hughes
- Connective Tissue Biology Laboratory, School of Biosciences, Cardiff University, Museum Avenue, Cathays Park, Cardiff CF10 3US, United Kingdom
| | - Bruce Caterson
- Connective Tissue Biology Laboratory, School of Biosciences, Cardiff University, Museum Avenue, Cathays Park, Cardiff CF10 3US, United Kingdom
| | - Akira Tanigami
- Otsuka GEN Research Institute, Otsuka Pharmaceutical Co. Ltd., Tokushima 771-0192, Japan
| | - Jun Nakayama
- Department of Pathology, Shinshu University School of Medicine, Matsumoto 390-8621, Japan; and
| | - Michiko N. Fukada
- Glycobiology Program, Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037
| | - Yasuo Tano
- *Department of Ophthalmology, Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kohji Nishida
- **Department of Ophthalmology, Tohoku University Medical School, 1-1 Seiryo-cho, Aobaku, Sendai, Miyagi 980-8574, Japan
| | - Andrew J. Quantock
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Redwood Building, Cathays Park, Cardiff CF10 3NB, United Kingdom
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108
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Kao WWY, Funderburgh JL, Xia Y, Liu CY, Conrad GW. Focus on molecules: lumican. Exp Eye Res 2005; 82:3-4. [PMID: 16213485 PMCID: PMC2876311 DOI: 10.1016/j.exer.2005.08.012] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Revised: 08/06/2005] [Accepted: 08/11/2005] [Indexed: 11/19/2022]
Affiliation(s)
- Winston W-Y Kao
- Department of Ophthalmology, University of Cincinnati, Cincinnati, OH, USA.
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