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Poole K, Iyer KS, Schmidtke DW, Petroll WM, Varner VD. Corneal keratocytes, fibroblasts, and myofibroblasts exhibit distinct transcriptional profiles in vitro. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.28.582620. [PMID: 38464034 PMCID: PMC10925317 DOI: 10.1101/2024.02.28.582620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Purpose After stromal injury to the cornea, the release of growth factors and pro-inflammatory cytokines promotes the activation of quiescent keratocytes into a migratory fibroblast and/or fibrotic myofibroblast phenotype. Persistence of the myofibroblast phenotype can lead to corneal fibrosis and scarring, which are leading causes of blindness worldwide. This study aims to establish comprehensive transcriptional profiles for cultured corneal keratocytes, fibroblasts, and myofibroblasts to gain insights into the mechanisms through which these phenotypic changes occur. Methods Primary rabbit corneal keratocytes were cultured in either defined serum-free media (SF), fetal bovine serum (FBS) containing media, or in the presence of TGF-β1 to induce keratocyte, fibroblast, or myofibroblast phenotypes, respectively. Bulk RNA sequencing followed by bioinformatic analyses was performed to identify significant differentially expressed genes (DEGs) and enriched biological pathways for each phenotype. Results Genes commonly associated with keratocytes, fibroblasts, or myofibroblasts showed high relative expression in SF, FBS, or TGF-β1 culture conditions, respectively. Differential expression and functional analyses revealed novel DEGs for each cell type, as well as enriched pathways indicative of differences in proliferation, apoptosis, extracellular matrix (ECM) synthesis, cell-ECM interactions, cytokine signaling, and cell mechanics. Conclusions Overall, these data demonstrate distinct transcriptional differences among cultured corneal keratocytes, fibroblasts, and myofibroblasts. We have identified genes and signaling pathways that may play important roles in keratocyte differentiation, including many related to mechanotransduction and ECM biology. Our findings have revealed novel molecular markers for each cell type, as well as possible targets for modulating cell behavior and promoting physiological corneal wound healing.
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Matejkova J, Kanokova D, Supova M, Matejka R. A New Method for the Production of High-Concentration Collagen Bioinks with Semiautonomic Preparation. Gels 2024; 10:66. [PMID: 38247788 PMCID: PMC10815100 DOI: 10.3390/gels10010066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 01/05/2024] [Accepted: 01/11/2024] [Indexed: 01/23/2024] Open
Abstract
It is believed that 3D bioprinting will greatly help the field of tissue engineering and regenerative medicine, as live patient cells are incorporated into the material, which directly creates a 3D structure. Thus, this method has potential in many types of human body tissues. Collagen provides an advantage, as it is the most common extracellular matrix present in all kinds of tissues and is, therefore, very natural for cells and the organism. Hydrogels with highly concentrated collagen make it possible to create 3D structures without additional additives to crosslink the polymer, which could negatively affect cell proliferation and viability. This study established a new method for preparing highly concentrated collagen bioinks, which does not negatively affect cell proliferation and viability. The method is based on two successive neutralizations of the prepared hydrogel using the bicarbonate buffering mechanisms of the 2× enhanced culture medium and pH adjustment by adding NaOH. Collagen hydrogel was used in concentrations of 20 and 30 mg/mL dissolved in acetic acid with a concentration of 0.05 and 0.1 wt.%. The bioink preparation process is automated, including colorimetric pH detection and adjustment. The new method was validated using bioprinting and subsequent cultivation of collagen hydrogels with incorporated stromal cells. After 96 h of cultivation, cell proliferation and viability were not statistically significantly reduced.
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Affiliation(s)
- Jana Matejkova
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, 272 01 Kladno, Czech Republic;
| | - Denisa Kanokova
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, 272 01 Kladno, Czech Republic;
| | - Monika Supova
- Department of Composites and Carbon Materials, Institute of Rock Structure and Mechanics of The Czech Academy of Sciences, v.v.i., 182 09 Prague, Czech Republic;
| | - Roman Matejka
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, 272 01 Kladno, Czech Republic;
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Feliciano AJ, Grant R, Fernández-Pérez J, Giselbrecht S, Baker MB. Introducing Dynamicity: Engineering Stress Relaxation Into Hydrogels Via Thiol-Ene Modified Alginate for Mechanobiological in vitro Modeling of the Cornea. Macromol Biosci 2024; 24:e2300109. [PMID: 37401723 DOI: 10.1002/mabi.202300109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 06/11/2023] [Accepted: 06/23/2023] [Indexed: 07/05/2023]
Abstract
Developing biomaterials for corneal repair and regeneration is crucial for maintaining clear vision. The cornea, a specialized tissue, relies on corneal keratocytes, that respond to their mechanical environment. Altering stiffness affects keratocyte behavior, but static stiffness alone cannot capture the dynamic properties of in vivo tissue. This study proposes that the cornea exhibits time-dependent mechanical properties, similar to other tissues, and aims to replicate these properties in potential therapeutic matrices. First, the cornea's stress relaxation properties are investigated using nanoindentation, revealing 15% relaxation within 10 seconds. Hydrogel dynamicity is then modulated using a specially formulated alginate-PEG and alginate-norbornene mixture. The tuning of the hydrogel's dynamicity is achieved through a photoinitiated norbornene-norbornene dimerization reaction, resulting in relaxation times ranging from 30 seconds to 10 minutes. Human primary corneal keratocytes are cultured on these hydrogels, demonstrating reduced αSMA (alpha smooth muscle actin) expression and increased filopodia formation on slower relaxing hydrogels, resembling their native phenotype. This in vitro model can enable the optimization of stress relaxation for various cell types, including corneal keratocytes, to control tissue formation. Combining stress relaxation optimization with stiffness assessment provides a more accurate tool for studying cell behavior and reduces mechanical mismatch with native tissues in implanted constructs.
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Affiliation(s)
- Antonio J Feliciano
- Department of Complex Tissue Regeneration, MERLN Institute, Maastricht University, Maastricht, Netherlands
| | - Rhiannon Grant
- Department of Instructive Biomaterials Engineering, MERLN Institute, Maastricht University, Maastricht, Netherlands
| | - Julia Fernández-Pérez
- Department of Complex Tissue Regeneration, MERLN Institute, Maastricht University, Maastricht, Netherlands
| | - Stefan Giselbrecht
- Department of Instructive Biomaterials Engineering, MERLN Institute, Maastricht University, Maastricht, Netherlands
| | - Matthew B Baker
- Department of Complex Tissue Regeneration, MERLN Institute, Maastricht University, Maastricht, Netherlands
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Fukasaku H, Meguro A, Takeuchi M, Mizuki N, Ota M, Funakoshi K. Association of PDGFRA polymorphisms with the risk of corneal astigmatism in a Japanese population. Sci Rep 2023; 13:16075. [PMID: 37752244 PMCID: PMC10522672 DOI: 10.1038/s41598-023-43333-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 09/22/2023] [Indexed: 09/28/2023] Open
Abstract
Corneal astigmatism is reportedly associated with polymorphisms of the platelet-derived growth factor receptor alpha (PDGFRA) gene region in Asian populations of Chinese, Malay, and Indian ancestry and populations of European ancestry. In this study, we investigated whether these PDGFRA polymorphisms are associated with corneal astigmatism in a Japanese population. We recruited 1,535 cases with corneal astigmatism (mean corneal cylinder power across both eyes: ≤ - 0.75 diopters [D]) and 842 controls (> - 0.75 D) to genotype 13 single-nucleotide polymorphisms (SNPs) in the PDGFRA gene region. We also performed imputation analysis in the region, with 179 imputed SNPs included in the statistical analyses. The PDGFRA SNPs were not significantly associated with the cases with corneal astigmatism ≤ - 0.75 D. However, the odds ratios (ORs) of the minor alleles of SNPs in the upstream region of PDGFRA, including rs7673984, rs4864857, and rs11133315, tended to increase according to the degree of corneal astigmatism, and these SNPs were significantly associated with the cases with corneal astigmatism ≤ - 1.25 D or ≤ - 1.50 D (Pc < 0.05, OR = 1.34-1.39). These results suggest that PDGFRA SNPs play a potential role in the development of greater corneal astigmatism.
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Affiliation(s)
- Hideharu Fukasaku
- Department of Neuroanatomy, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, 236-0004, Japan
- Fukasaku Eye Institute, Yokohama, Kanagawa, 220-0003, Japan
| | - Akira Meguro
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, 236-0004, Japan.
- Department of Advanced Medicine for Ocular Diseases, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, 236-0004, Japan.
| | - Masaki Takeuchi
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, 236-0004, Japan
- Department of Advanced Medicine for Ocular Diseases, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, 236-0004, Japan
| | - Nobuhisa Mizuki
- Department of Ophthalmology and Visual Science, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, 236-0004, Japan
- Department of Advanced Medicine for Ocular Diseases, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, 236-0004, Japan
| | - Masao Ota
- Department of Advanced Medicine for Ocular Diseases, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, 236-0004, Japan
- Department of Medicine, Division of Hepatology and Gastroenterology, Shinshu University School of Medicine, Matsumoto, Nagano, 390-8621, Japan
| | - Kengo Funakoshi
- Department of Neuroanatomy, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa, 236-0004, Japan
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Petroll WM, Miron-Mendoza M, Sunkara Y, Ikebe HR, Sripathi NR, Hassaniardekani H. The impact of UV cross-linking on corneal stromal cell migration, differentiation and patterning. Exp Eye Res 2023; 233:109523. [PMID: 37271309 PMCID: PMC10825899 DOI: 10.1016/j.exer.2023.109523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 05/09/2023] [Accepted: 06/01/2023] [Indexed: 06/06/2023]
Abstract
Previous studies have demonstrated that UV cross-linking (CXL) increases stromal stiffness and produces alterations in extracellular matrix (ECM) microstructure. In order to investigate how CXL impacts both keratocyte differentiation and patterning within the stroma, and fibroblast migration and myofibroblast differentiation on top of the stroma, we combined CXL with superficial phototherapeutic keratectomy (PTK) in a rabbit model. Twenty-six rabbits underwent a 6 mm diameter, 70 μm deep phototherapeutic keratectomy (PTK) with an excimer laser to remove the epithelium and anterior basement membrane. In 14 rabbits, standard CXL was performed in the same eye immediately after PTK. Contralateral eyes served as controls. In vivo confocal microscopy through focusing (CMTF) was used to analyze corneal epithelial and stromal thickness, as well as stromal keratocyte activation and corneal haze. CMTF scans were collected pre-operatively, and from 7 to 120 days after the procedure. A subset of rabbits was sacrificed at each time point, and corneas were fixed and labeled in situ for multiphoton fluorescence microscopy and second harmonic generation imaging. In vivo and in situ imaging demonstrated that haze after PTK was primarily derived from a layer of myofibroblasts that formed on top of the native stroma. Over time, this fibrotic layer was remodeled into more transparent stromal lamellae, and quiescent cells replaced myofibroblasts. Migrating cells within the native stroma underneath the photoablated area were elongated, co-aligned with collagen, and lacked stress fibers. In contrast, following PTK + CXL, haze was derived primarily from highly reflective necrotic "ghost cells" in the anterior stroma, and fibrosis on top of the photoablated stroma was not observed at any time point evaluated. Cells formed clusters as they migrated into the cross-linked stromal tissue and expressed stress fibers; some cells at the edge of the CXL area also expressed α-SM actin, suggesting myofibroblast transformation. Stromal thickness increased significantly between 21 and 90 days after PTK + CXL (P < 0.001) and was over 35 μm higher than baseline at Day 90 (P < 0.05). Overall, these data suggest that cross-linking inhibits interlamellar cell movement, and that these changes lead to a disruption of normal keratocyte patterning and increased activation during stromal repopulation. Interestingly, CXL also prevents PTK-induced fibrosis on top of the stroma, and results in long term increases in stromal thickness in the rabbit model.
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Affiliation(s)
- W Matthew Petroll
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA; Department of Biomedical Engineering, UT Southwestern Medical Center, Dallas, TX, USA.
| | | | - Yukta Sunkara
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Hikaru R Ikebe
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Nishith R Sripathi
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
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Pot SA, Lin Z, Shiu J, Benn MC, Vogel V. Growth factors and mechano-regulated reciprocal crosstalk with extracellular matrix tune the keratocyte-fibroblast/myofibroblast transition. Sci Rep 2023; 13:11350. [PMID: 37443325 PMCID: PMC10345140 DOI: 10.1038/s41598-023-37776-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
Improper healing of the cornea after injury, infections or surgery can lead to corneal scar formation, which is associated with the transition of resident corneal keratocytes into activated fibroblasts and myofibroblasts (K-F/M). Myofibroblasts can create an extracellular matrix (ECM) niche in which fibrosis is promoted and perpetuated, resulting in progressive tissue opacification and vision loss. As a reversion back to quiescent keratocytes is essential to restore corneal transparency after injury, we characterized how growth factors with demonstrated profibrotic effects (PDGF, FGF, FBS, TGFβ1) induce the K-F/M transition, and whether their withdrawal can revert it. Indeed, the upregulated expression of αSMA and the associated changes in cytoskeletal architecture correlated with increases in cell contractility, fibronectin (Fn) and collagen matrix density and Fn fiber strain, as revealed by 2D cell culture, nanopillar cellular force mapping and a FRET-labeled Fn tension probe. Substrate mechanosensing drove a more complete K-F/M transition reversal following growth factor withdrawal on nanopillar arrays than on planar glass substrates. Using decellularized ECM scaffolds, we demonstrated that the K-F/M transition was inhibited in keratocytes reseeded onto myofibroblast-assembled, and/or collagen-1-rich ECM. This supports the presence of a myofibroblast-derived ECM niche that contains cues favoring tissue homeostasis rather than fibrosis.
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Affiliation(s)
- Simon A Pot
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland.
- Ophthalmology Section, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057, Zurich, Switzerland.
| | - Zhe Lin
- Ruisi (Fujian) Biomedical Engineering Research Center Co Ltd, 26-1 Wulongjiang Road, Fuzhou, 350100, People's Republic of China
| | - Jauye Shiu
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland
- Graduate Institute of Biomedical Sciences, China Medical University, No. 91, Xueshi Rd, North District, Taichung City, Taiwan
| | - Mario C Benn
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland
| | - Viola Vogel
- Laboratory of Applied Mechanobiology, Department of Health Sciences and Technology, ETH Zurich, Vladimir-Prelog-Weg 4, 8093, Zurich, Switzerland.
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7
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Akoto T, Cai J, Nicholas S, McCord H, Estes AJ, Xu H, Karamichos D, Liu Y. Unravelling the Impact of Cyclic Mechanical Stretch in Keratoconus-A Transcriptomic Profiling Study. Int J Mol Sci 2023; 24:7437. [PMID: 37108600 PMCID: PMC10139219 DOI: 10.3390/ijms24087437] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/04/2023] [Accepted: 04/16/2023] [Indexed: 04/29/2023] Open
Abstract
Biomechanical and molecular stresses may contribute to the pathogenesis of keratoconus (KC). We aimed to profile the transcriptomic changes in healthy primary human corneal (HCF) and KC-derived cells (HKC) combined with TGFβ1 treatment and cyclic mechanical stretch (CMS), mimicking the pathophysiological condition in KC. HCFs (n = 4) and HKCs (n = 4) were cultured in flexible-bottom collagen-coated 6-well plates treated with 0, 5, and 10 ng/mL of TGFβ1 with or without 15% CMS (1 cycle/s, 24 h) using a computer-controlled Flexcell FX-6000T Tension system. We used stranded total RNA-Seq to profile expression changes in 48 HCF/HKC samples (100 bp PE, 70-90 million reads per sample), followed by bioinformatics analysis using an established pipeline with Partek Flow software. A multi-factor ANOVA model, including KC, TGFβ1 treatment, and CMS, was used to identify differentially expressed genes (DEGs, |fold change| ≥ 1.5, FDR ≤ 0.1, CPM ≥ 10 in ≥1 sample) in HKCs (n = 24) vs. HCFs (n = 24) and those responsive to TGFβ1 and/or CMS. PANTHER classification system and the DAVID bioinformatics resources were used to identify significantly enriched pathways (FDR ≤ 0.05). Using multi-factorial ANOVA analyses, 479 DEGs were identified in HKCs vs. HCFs including TGFβ1 treatment and CMS as cofactors. Among these DEGs, 199 KC-altered genes were responsive to TGFβ1, thirteen were responsive to CMS, and six were responsive to TGFβ1 and CMS. Pathway analyses using PANTHER and DAVID indicated the enrichment of genes involved in numerous KC-relevant functions, including but not limited to degradation of extracellular matrix, inflammatory response, apoptotic processes, WNT signaling, collagen fibril organization, and cytoskeletal structure organization. TGFβ1-responsive KC DEGs were also enriched in these. CMS-responsive KC-altered genes such as OBSCN, CLU, HDAC5, AK4, ITGA10, and F2RL1 were identified. Some KC-altered genes, such as CLU and F2RL1, were identified to be responsive to both TGFβ1 and CMS. For the first time, our multi-factorial RNA-Seq study has identified many KC-relevant genes and pathways in HKCs with TGFβ1 treatment under CMS, suggesting a potential role of TGFβ1 and biomechanical stretch in KC development.
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Affiliation(s)
- Theresa Akoto
- Department of Cellular Biology & Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Jingwen Cai
- Department of Cellular Biology & Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Sarah Nicholas
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
- Department of Pharmaceutical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Hayden McCord
- Department of Cellular Biology & Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Amy J. Estes
- Department of Ophthalmology, Augusta University, Augusta, GA 30912, USA
- James & Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Hongyan Xu
- Department of Population Health Sciences, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Dimitrios Karamichos
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
- Department of Pharmaceutical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Yutao Liu
- Department of Cellular Biology & Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- James & Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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Lam KH, Shihabeddin TZ, Awkal JA, Najjar AM, Miron-Mendoza M, Maruri DP, Varner VD, Petroll WM, Schmidtke DW. Effects of Topography and PDGF on the Response of Corneal Keratocytes to Fibronectin-Coated Surfaces. J Funct Biomater 2023; 14:217. [PMID: 37103307 PMCID: PMC10144166 DOI: 10.3390/jfb14040217] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/30/2023] [Accepted: 04/07/2023] [Indexed: 04/28/2023] Open
Abstract
During corneal wound healing, corneal keratocytes are exposed to both biophysical and soluble cues that cause them to transform from a quiescent state to a repair phenotype. How keratocytes integrate these multiple cues simultaneously is not well understood. To investigate this process, primary rabbit corneal keratocytes were cultured on substrates patterned with aligned collagen fibrils and coated with adsorbed fibronectin. After 2 or 5 days of culture, keratocytes were fixed and stained to assess changes in cell morphology and markers of myofibroblastic activation by fluorescence microscopy. Initially, adsorbed fibronectin had an activating effect on the keratocytes as evidenced by changes in cell shape, stress fiber formation, and expression of alpha-smooth muscle actin (α-SMA). The magnitude of these effects depended upon substrate topography (i.e., flat substrate vs aligned collagen fibrils) and decreased with culture time. When keratocytes were simultaneously exposed to adsorbed fibronectin and soluble platelet-derived growth factor-BB (PDGF-BB), the cells elongated and had reduced expression of stress fibers and α-SMA. In the presence of PDGF-BB, keratocytes plated on the aligned collagen fibrils elongated in the direction of the fibrils. These results provide new information on how keratocytes respond to multiple simultaneous cues and how the anisotropic topography of aligned collagen fibrils influences keratocyte behavior.
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Affiliation(s)
- Kevin H. Lam
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Tarik Z. Shihabeddin
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Jacob A. Awkal
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Alex M. Najjar
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Miguel Miron-Mendoza
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Daniel P. Maruri
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
| | - Victor D. Varner
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
- Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - W. Matthew Petroll
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Biomedical Engineering, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - David W. Schmidtke
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA
- Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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van der Putten C, van den Broek D, Kurniawan NA. Myofibroblast transdifferentiation of keratocytes results in slower migration and lower sensitivity to mesoscale curvatures. Front Cell Dev Biol 2022; 10:930373. [PMID: 35938166 PMCID: PMC9355510 DOI: 10.3389/fcell.2022.930373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 07/01/2022] [Indexed: 11/15/2022] Open
Abstract
Functional tissue repair after injury or disease is governed by the regenerative or fibrotic response by cells within the tissue. In the case of corneal damage, keratocytes are a key cell type that determine the outcome of the remodeling response by either adapting to a fibroblast or myofibroblast phenotype. Although a growing body of literature indicates that geometrical cues in the environment can influence Myo(fibroblast) phenotype, there is a lack of knowledge on whether and how differentiated keratocyte phenotype is affected by the curved tissue geometry in the cornea. To address this gap, in this study we characterized the phenotype of fibroblastic and transforming growth factor β (TGFβ)-induced myofibroblastic keratocytes and studied their migration behavior on curved culture substrates with varying curvatures. Immunofluorescence staining and quantification of cell morphological parameters showed that, generally, fibroblastic keratocytes were more likely to elongate, whereas myofibroblastic keratocytes expressed more pronounced α smooth muscle actin (α-SMA) and actin stress fibers as well as more mature focal adhesions. Interestingly, keratocyte adhesion on convex structures was weak and unstable, whereas they adhered normally on flat and concave structures. On concave cylinders, fibroblastic keratocytes migrated faster and with higher persistence along the longitudinal direction compared to myofibroblastic keratocytes. Moreover, this behavior became more pronounced on smaller cylinders (i.e., higher curvatures). Taken together, both keratocyte phenotypes can sense and respond to the sign and magnitude of substrate curvatures, however, myofibroblastic keratocytes exhibit weaker curvature sensing and slower migration on curved substrates compared to fibroblastic keratocytes. These findings provide fundamental insights into keratocyte phenotype after injury, but also exemplify the potential of tuning the physical cell environments in tissue engineering settings to steer towards a favorable regeneration response.
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Affiliation(s)
- Cas van der Putten
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, Netherlands
| | - Daniëlle van den Broek
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, Netherlands
| | - Nicholas A. Kurniawan
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, Netherlands
- *Correspondence: Nicholas A. Kurniawan,
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Iyer KS, Maruri DP, Peak KE, Schmidtke DW, Petroll WM, Varner VD. ECM stiffness modulates the proliferation but not the motility of primary corneal keratocytes in response to PDGF-BB. Exp Eye Res 2022; 220:109112. [PMID: 35595094 PMCID: PMC10163834 DOI: 10.1016/j.exer.2022.109112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/25/2022] [Accepted: 05/11/2022] [Indexed: 11/04/2022]
Abstract
During corneal wound healing, keratocytes present within the corneal stroma become activated into a repair phenotype upon the release of growth factors, such as transforming growth factor-beta 1 (TGF-β1) and platelet-derived growth factor-BB (PDGF-BB). The process of injury and repair can lead to changes in the mechanical properties of the tissue, and previous work has shown that the TGF-β1-mediated myofibroblast differentiation of corneal keratocytes depends on substratum stiffness. It is still unclear, however, if changes in stiffness can modulate keratocyte behavior in response to other growth factors, such as PDGF-BB. Here, we used a polyacrylamide (PA) gel system to determine whether changes in stiffness influence the proliferation and motility of primary corneal keratocytes treated with PDGF-BB. In the presence of PDGF-BB, cells on stiffer substrata exhibited a more elongated morphology and had higher rates of proliferation than cells in a more compliant microenvironment. Using a freeze-injury to assay cell motility, however, we did not observe any stiffness-dependent differences in the migration of keratocytes treated with PDGF-BB. Taken together, these data highlight the importance of biophysical cues during corneal wound healing and suggest that keratocytes respond differently to changes in ECM stiffness in the presence of different growth factors.
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Affiliation(s)
- Krithika S Iyer
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA
| | - Daniel P Maruri
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA
| | - Kara E Peak
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA
| | - David W Schmidtke
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA; Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA
| | - W Matthew Petroll
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Victor D Varner
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX, USA; Department of Surgery, UT Southwestern Medical Center, Dallas, TX, USA.
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11
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Sugioka K, Nishida T, Kodama-Takahashi A, Murakami J, Mano F, Okada K, Fukuda M, Kusaka S. Urokinase-type plasminogen activator (uPA) negatively regulates α-smooth muscle actin expression via Endo180 and the uPA receptor in corneal fibroblasts. Am J Physiol Cell Physiol 2022; 323:C104-C115. [PMID: 35649252 DOI: 10.1152/ajpcell.00432.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Corneal fibroblasts are embedded within an extracellular matrix composed largely of collagen type 1, proteoglycans, and other proteins in the corneal stroma, and their morphology and function are subject to continuous regulation by collagen. During wound healing and in various pathological conditions, corneal fibroblasts differentiate into myofibroblasts characterized by the expression of α-smooth muscle actin (α-SMA). Endo180, also known as urokinase-type plasminogen activator (uPA) receptor-associated protein (uPARAP), is a collagen receptor. Here we investigated whether targeting of Endo180 and the uPA receptor (uPAR) by uPA might play a role in the regulation of α-SMA expression by culturing corneal fibroblasts derived from uPA-deficient (uPA-/-) or wild-type (uPA+/+) mice in a collagen gel or on plastic. The expression of α-SMA was upregulated, the amounts of full-length Endo180 and uPAR were increased, and the levels of both transforming growth factor-b (TGF-β) expression and Smad3 phosphorylation were higher in uPA-/- corneal fibroblasts compared with uPA+/+ cells under the collagen gel culture condition. Antibodies to Endo180 inhibited these effects of uPA deficiency on a-SMA and TGF-b expression, whereas a TGF-b signaling inhibitor blocked the effects on Smad3 phosphorylation and a-SMA expression. Our results suggest that uPA deficiency might promote the interaction between collagen and Endo180 and thereby increase a-SMA expression in a manner dependent on TGF-β signaling. Expression of α-SMA is thus negatively regulated by uPA through targeting of Endo180 and uPAR.
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Affiliation(s)
- Koji Sugioka
- Department of Ophthalmology, Kindai University Nara Hospital, Ikoma City, Nara, Japan.,Department of Ophthalmology, Kindai University Hospital, Osakasayama City, Osaka, Japan
| | - Teruo Nishida
- Department of Ophthalmology, Kindai University Nara Hospital, Ikoma City, Nara, Japan.,Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube City, Yamaguchi, Japan.,Division of Cornea and Ocular Surface, Ohshima Eye Hospital, Fukuoka City, Fukuoka, Japan
| | - Aya Kodama-Takahashi
- Department of Ophthalmology, Kindai University Nara Hospital, Ikoma City, Nara, Japan
| | | | - Fukutaro Mano
- Department of Ophthalmology, Kindai University Hospital, Osakasayama City, Osaka, Japan
| | - Kiyotaka Okada
- Department of Arts and Science, Kindai University Faculty of Medicine, Osakasayama City, Osaka, Japan
| | - Masahiko Fukuda
- Department of Ophthalmology, Kindai University Nara Hospital, Ikoma City, Nara, Japan
| | - Shunji Kusaka
- Department of Ophthalmology, Kindai University Hospital, Osakasayama City, Osaka, Japan
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12
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Darvish DM. Collagen fibril formation in vitro: From origin to opportunities. Mater Today Bio 2022; 15:100322. [PMID: 35757034 PMCID: PMC9218154 DOI: 10.1016/j.mtbio.2022.100322] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 06/07/2022] [Accepted: 06/09/2022] [Indexed: 12/13/2022] Open
Abstract
Sometimes, to move forward, it is necessary to look back. Collagen type I is one of the most commonly used biomaterials in tissue engineering and regenerative medicine. There are a variety of collagen scaffolds and biomedical products based on collagen have been made, and the development of new ones is still ongoing. Materials, where collagen is in the fibrillar form, have some advantages: they have superior mechanical properties, higher degradation time and, what is most important, mimic the structure of the native extracellular matrix. There are some standard protocols for the formation of collagen fibrils in vitro, but if we look more carefully at those methods, we can see some controversies. For example, why is the formation of collagen gel commonly carried out at 37 °C, when it was well investigated that the temperature higher than 35 °C results in a formation of not well-ordered fibrils? Biomimetic collagen materials can be obtained both using culture medium or neutralizing solution, but it requires a deep understanding of all of the crucial points. One of this point is collagen extraction method, since not every method retains the ability of collagen to reconstitute native banded fibrils. Collagen polymorphism is also often overlooked in spite of the appearance of different polymorphic forms during fibril formation is possible, especially when collagen blends are utilized. In this review, we will not only pay attention to these issues, but we will overview the most prominent works related to the formation of collagen fibrils in vitro starting from the first approaches and moving to the up-to-date recipes.
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Affiliation(s)
- Diana M Darvish
- Institute of Cytology of the Russian Academy of Sciences, Tikhoretsky Prospekt, 4, Saint-Petersburg, 194064, Russia
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13
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Zhang Y, Zhou K, Feng Z, Feng K, Ji Y, Li C, Huang Z. Viscoelastic properties' characterization of corneal stromal models using non-contact surface acoustic wave optical coherence elastography (SAW-OCE). JOURNAL OF BIOPHOTONICS 2022; 15:e202100253. [PMID: 34713598 DOI: 10.1002/jbio.202100253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/20/2021] [Accepted: 10/27/2021] [Indexed: 06/13/2023]
Abstract
Viscoelastic characterization of the tissue-engineered corneal stromal model is important for our understanding of the cell behaviors in the pathophysiologic altered corneal extracellular matrix (ECM). The effects of the interactions between stromal cells and different ECM characteristics on the viscoelastic properties during an 11-day culture period were explored. Collagen-based hydrogels seeded with keratocytes were used to replicate human corneal stroma. Keratocytes were seeded at 8 × 103 cells per hydrogel and with collagen concentrations of 3, 5 and 7 mg/ml. Air-pulse-based surface acoustic wave optical coherence elastography (SAW-OCE) was employed to monitor the changes in the hydrogels' dimensions and viscoelasticity over the culture period. The results showed the elastic modulus increased by 111%, 56% and 6%, and viscosity increased by 357%, 210% and 25% in the 3, 5 and 7 mg/ml hydrogels, respectively. To explain the SAW-OCE results, scanning electron microscope was also performed. The results confirmed the increase in elastic modulus and viscosity of the hydrogels, respectively, arose from increased fiber density and force-dependent unbinding of bonds between collagen fibers. This study reveals the influence of cell-matrix interactions on the viscoelastic properties of corneal stromal models and can provide quantitative guidance for mechanobiological investigations which require collagen ECM with tuneable viscoelastic properties.
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Affiliation(s)
- Yilong Zhang
- School of Science and Engineering, University of Dundee, Dundee, UK
| | - Kanheng Zhou
- School of Science and Engineering, University of Dundee, Dundee, UK
| | - Zhengshuyi Feng
- School of Science and Engineering, University of Dundee, Dundee, UK
| | - Kairui Feng
- School of Science and Engineering, University of Dundee, Dundee, UK
| | - Yubo Ji
- School of Science and Engineering, University of Dundee, Dundee, UK
| | - Chunhui Li
- School of Science and Engineering, University of Dundee, Dundee, UK
| | - Zhihong Huang
- School of Science and Engineering, University of Dundee, Dundee, UK
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14
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Stepanovska J, Otahal M, Hanzalek K, Supova M, Matejka R. pH Modification of High-Concentrated Collagen Bioinks as a Factor Affecting Cell Viability, Mechanical Properties, and Printability. Gels 2021; 7:gels7040252. [PMID: 34940312 PMCID: PMC8700843 DOI: 10.3390/gels7040252] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/25/2021] [Accepted: 12/03/2021] [Indexed: 12/17/2022] Open
Abstract
The 3D bioprinting of cell-incorporated gels is a promising direction in tissue engineering applications. Collagen-based hydrogels, due to their similarity to extracellular matrix tissue, can be a good candidate for bioink and 3D bioprinting applications. However, low hydrogel concentrations of hydrogel (<10 mg/mL) provide insufficient structural support and, in highly concentrated gels, cell proliferation is reduced. In this study, we showed that it is possible to print highly concentrated collagen hydrogels with incorporated cells, where the viability of the cells in the gel remains very good. This can be achieved simply by optimizing the properties of the bioink, particularly the gel composition and pH modification, as well as by optimizing the printing parameters. The bioink composed of porcine collagen hydrogel with a collagen concentration of 20 mg/mL was tested, while the final bioink collagen concentration was 10 mg/mL. This bioink was modified with 0, 5, 9, 13, 17 and 20 μL/mL of 1M NaOH solution, which affected the resulting pH and gelling time. Cylindrical samples based on the given bioink, with the incorporation of porcine adipose-derived stromal cells, were printed with a custom 3D bioprinter. These constructs were cultivated in static conditions for 6 h, and 3 and 5 days. Cell viability and morphology were evaluated. Mechanical properties were evaluated by means of a compression test. Our results showed that optimal composition and the addition of 13 μL NaOH per mL of bioink adjusted the pH of the bioink enough to allow cells to grow and divide. This modification also contributed to a higher elastic modulus, making it possible to print structures up to several millimeters with sufficient mechanical resistance. We optimized the bioprinter parameters for printing low-viscosity bioinks. With this experiment, we showed that a high concentration of collagen gels may not be a limiting factor for cell proliferation.
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Affiliation(s)
- Jana Stepanovska
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna 3105, 272 01 Kladno, Czech Republic; (J.S.); (K.H.)
| | - Martin Otahal
- Department of Natural Sciences, Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna 3105, 272 01 Kladno, Czech Republic;
| | - Karel Hanzalek
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna 3105, 272 01 Kladno, Czech Republic; (J.S.); (K.H.)
| | - Monika Supova
- Department of Composites and Carbon Materials, Institute of Rock Structure and Mechanics, Czech Academy of Sciences, 182 09 Prague, Czech Republic;
| | - Roman Matejka
- Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Sitna 3105, 272 01 Kladno, Czech Republic; (J.S.); (K.H.)
- Correspondence: ; Tel.: +420-224-359-936
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15
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Lam TN, Nicholas SE, Choi A, Ma JX, Karamichos D. Cellular Contractility Profiles of Human Diabetic Corneal Stromal Cells. Anal Cell Pathol (Amst) 2021; 2021:9913210. [PMID: 34194958 PMCID: PMC8203386 DOI: 10.1155/2021/9913210] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 05/27/2021] [Indexed: 11/17/2022] Open
Abstract
Diabetic keratopathy is a corneal complication of diabetes mellitus (DM). Patients with diabetic keratopathy are prone to developing corneal haze, scarring, recurrent erosions, and significant wound healing defects/delays. The purpose of this study was to determine the contractility profiles in the diabetic human corneal stromal cells and characterize their molecular signatures. Primary human corneal fibroblasts from healthy, Type 1 DM (T1DM), and Type 2 DM (T2DM) donors were cultured using an established 3D collagen gel model. We tracked, measured, and quantified the contractile footprint over 9 days and quantified the modulation of specific corneal/diabetes markers in the conditional media and cell lysates using western blot analysis. Human corneal fibroblasts (HCFs) exhibited delayed and decreased contractility compared to that from T1DMs and T2DMs. Compared to HCFs, T2DMs demonstrated an initial downregulation of collagen I (day 3), followed by a significant upregulation by day 9. Collagen V was significantly upregulated in both T1DMs and T2DMs based on basal secretion, when compared to HCFs. Cell lysates were upregulated in the myofibroblast-associated marker, α-smooth muscle actin, in T2DMs on day 9, corresponding to the significant increase in contractility rate observed at the same time point. Furthermore, our data demonstrated a significant upregulation in IGF-1 expression in T2DMs, when compared to HCFs and T1DMs, at day 9. T1DMs demonstrated significant downregulation of IGF-1 expression, when compared to HCFs. Overall, both T1DMs and T2DMs exhibited increased contractility associated with fibrotic phenotypes. These findings, and future studies, may contribute to better understanding of the pathobiology of diabetic keratopathy and ultimately the development of new therapeutic approaches.
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Affiliation(s)
- Thi N. Lam
- Dean McGee Eye Institute, Oklahoma University Health Sciences Center, 608 Stanton L Young Blvd, Oklahoma City, OK 73104, USA
| | - Sarah E. Nicholas
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX 76107, USA
- Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX 76107, USA
| | - Alexander Choi
- Dean McGee Eye Institute, Oklahoma University Health Sciences Center, 608 Stanton L Young Blvd, Oklahoma City, OK 73104, USA
| | - Jian-Xing Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young, Oklahoma City, OK, USA
- Harold Hamm Oklahoma Diabetes Center, 1000 N Lincoln Blvd, Oklahoma City, OK, USA
| | - Dimitrios Karamichos
- North Texas Eye Research Institute, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX 76107, USA
- Department of Pharmaceutical Sciences, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX 76107, USA
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX 76107, USA
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16
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Hasenzahl M, Müsken M, Mertsch S, Schrader S, Reichl S. Cell sheet technology: Influence of culture conditions on in vitro-cultivated corneal stromal tissue for regenerative therapies of the ocular surface. J Biomed Mater Res B Appl Biomater 2021; 109:1488-1504. [PMID: 33538123 DOI: 10.1002/jbm.b.34808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 01/11/2021] [Accepted: 01/14/2021] [Indexed: 11/11/2022]
Abstract
The in vitro reconstruction of stromal tissue by long-term cultivation of corneal fibroblasts is a smart approach for regenerative therapies of ocular surface diseases. However, systematic investigations evaluating optimized cultivation protocols for the realization of a biomaterial are lacking. This study investigated the influence of supplements to the culture media of human corneal fibroblasts on the formation of a cell sheet consisting of cells and extracellular matrix. Among the supplements studied are vitamin C, fetal bovine serum, L-glutamine, components of collagen such as L-proline, L-4-hydroxyproline and glycine, and TGF-β1, bFGF, IGF-2, PDGF-BB and insulin. After long-term cultivation, the proliferation, collagen and glycosaminoglycan content and light transmission of the cell sheets were examined. Biomechanical properties were investigated by tensile tests and the ultrastructure was characterized by electron microscopy, small-angle X-ray scattering, antibody staining and ELISA. The synthesis of extracellular matrix was significantly increased by cultivation with insulin or TGF-β1, each with vitamin C. The sheets exhibited a high transparency and suitable material properties. The production of a transparent, scaffold-free, potentially autologous, in vitro-generated construct by culturing fibroblasts with extracellular matrix synthesis-stimulating supplements represents a promising approach for a biomaterial that can be used for ocular surface reconstruction in slowly progressing diseases.
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Affiliation(s)
- Meike Hasenzahl
- Institut für Pharmazeutische Technologie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Mathias Müsken
- Helmholtz-Centre for Infection Research, Central Facility for Microscopy, Braunschweig, Germany
| | - Sonja Mertsch
- Laboratory of Experimental Ophthalmology, Department of Ophthalmology, Pius-Hospital, Carl von Ossietzky University, Oldenburg, Germany
| | - Stefan Schrader
- Laboratory of Experimental Ophthalmology, Department of Ophthalmology, Pius-Hospital, Carl von Ossietzky University, Oldenburg, Germany
| | - Stephan Reichl
- Institut für Pharmazeutische Technologie, Technische Universität Braunschweig, Braunschweig, Germany
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17
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Zhang Y, Ling Y, Zhang D, Wang M, Purslow C, Yang Y, Li C, Huang Z. Quantitative measurement of mechanical properties in wound healing processes in a corneal stroma model by using vibrational optical coherence elastography (OCE). BIOMEDICAL OPTICS EXPRESS 2021; 12:588-603. [PMID: 33659091 PMCID: PMC7899504 DOI: 10.1364/boe.404096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/16/2020] [Accepted: 11/17/2020] [Indexed: 05/11/2023]
Abstract
Corneal wound healing, caused by frequent traumatic injury to the cornea and increasing numbers of refractive surgeries, has become a vital clinical problem. In the cornea, wound healing is an extremely complicated process. However, little is known about how the biomechanical changes in wound healing response of the cornea. Collagen-based hydrogels incorporating corneal cells are suitable for replicating a three-dimensional (3D) equivalent of the cornea in-vitro. In this study, the mechanical properties of corneal stroma models were quantitatively monitored by a vibrational optical coherence elastography (OCE) system during continuous culture periods. Specifically, human corneal keratocytes were seeded at 5 × 105 cells/mL in the hydrogels with a collagen concentration of 3.0 mg/mL. The elastic modulus of the unwounded constructs increased from 2.950 ± 0.2 kPa to 11.0 ± 1.4 kPa, and the maximum thickness decreased from 1.034 ± 0.1 mm to 0.464 ± 0.09 mm during a 15-day culture period. Furthermore, a traumatic wound in the construct was introduced with a size of 500 µm. The elastic modulus of the neo-tissue in the wound area increased from 1.488 ± 0.4 kPa to 6.639 ± 0.3 kPa over 13 days. This study demonstrates that the vibrational OCE system is capable of quantitative monitoring the changes in mechanical properties of a corneal stroma wound model during continuous culture periods and improves our understanding on corneal wound healing processes.
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Affiliation(s)
- Yilong Zhang
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Yuting Ling
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Duo Zhang
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Mingkai Wang
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Christine Purslow
- Thea Pharmaceuticals Ltd, Keele University Science & Innovation Park, Innovation Way, Stoke-on-Trent, ST5 5NT, UK
| | - Ying Yang
- Guy Hilton Research Center, School of Pharmacy and Bioengineering, Keele University, Stoke-on-Trent, ST4 7QB, UK
| | - Chunhui Li
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
| | - Zhihong Huang
- School of Science and Engineering, University of Dundee, Dundee DD1 4HN, Scotland, UK
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18
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Hancox Z, Heidari Keshel S, Yousaf S, Saeinasab M, Shahbazi MA, Sefat F. The progress in corneal translational medicine. Biomater Sci 2020; 8:6469-6504. [PMID: 33174878 DOI: 10.1039/d0bm01209b] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cornea tissue is in high demand by tissue donation centres globally, and thus tissue engineering cornea, which is the main topic of corneal translational medicine, can serve as a limitless alternative to a donated human cornea tissue. Tissue engineering aims to produce solutions to the challenges associated with conventional cornea tissue, including transplantation and use of human amniotic membrane (HAM), which have issues with storage and immune rejection in patients. Accordingly, by carefully selecting biomaterials and fabrication methods to produce these therapeutic tissues, the demand for cornea tissue can be met, with an improved healing outcome for recipients with less associated harmful risks. In this review paper, we aim to present the recent advancements in the research and clinical applications of cornea tissue, applications including biomaterial selection, fabrication methods, scaffold structure, cellular response to these scaffolds, and future advancements of these techniques.
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Affiliation(s)
- Zoe Hancox
- Department of Biomedical and Electronics Engineering, School of Engineering, University of Bradford, Bradford, UK.
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19
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Petroll WM, Varner VD, Schmidtke DW. Keratocyte mechanobiology. Exp Eye Res 2020; 200:108228. [PMID: 32919993 PMCID: PMC7655662 DOI: 10.1016/j.exer.2020.108228] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/31/2020] [Accepted: 09/02/2020] [Indexed: 01/22/2023]
Abstract
In vivo, corneal keratocytes reside within a complex 3D extracellular matrix (ECM) consisting of highly aligned collagen lamellae, growth factors, and other extracellular matrix components, and are subjected to various mechanical stimuli during developmental morphogenesis, fluctuations in intraocular pressure, and wound healing. The process by which keratocytes convert changes in mechanical stimuli (e.g. local topography, applied force, ECM stiffness) into biochemical signaling is known as mechanotransduction. Activation of the various mechanotransductive pathways can produce changes in cell migration, proliferation, and differentiation. Here we review how corneal keratocytes respond to and integrate different biochemical and biophysical factors. We first highlight how growth factors and other cytokines regulate the activity of Rho GTPases, cytoskeletal remodeling, and ultimately the mechanical phenotype of keratocytes. We then discuss how changes in the mechanical properties of the ECM have been shown to regulate keratocyte behavior in sophisticated 2D and 3D experimental models of the corneal microenvironment. Finally, we discuss how ECM topography and protein composition can modulate cell phenotypes, and review the different methods of fabricating in vitro mimics of corneal ECM topography, novel approaches for examining topographical effects in vivo, and the impact of different ECM glycoproteins and proteoglycans on keratocyte behavior.
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Affiliation(s)
- W Matthew Petroll
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Victor D Varner
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA; Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - David W Schmidtke
- Department of Bioengineering, University of Texas at Dallas, Richardson, TX 75080, USA; Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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20
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Maruri DP, Miron-Mendoza M, Kivanany PB, Hack JM, Schmidtke DW, Petroll WM, Varner VD. ECM Stiffness Controls the Activation and Contractility of Corneal Keratocytes in Response to TGF-β1. Biophys J 2020; 119:1865-1877. [PMID: 33080219 DOI: 10.1016/j.bpj.2020.08.040] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/31/2020] [Accepted: 08/31/2020] [Indexed: 12/19/2022] Open
Abstract
After surgery or traumatic injury, corneal wound healing can cause a scarring response that stiffens the tissue and impairs ocular function. This fibrosis is caused in part by the activation of corneal keratocytes from a native mechanically quiescent state to an activated myofibroblastic state. This transformation is tied to signaling downstream of transforming growth factor-β1 (TGF-β1). Here, to better understand how biochemical and biophysical cues interact to regulate keratocyte activation and contractility, we cultured primary rabbit corneal keratocytes on flexible substrata of varying stiffness in the presence (or absence) of TGF-β1. Time-lapse fluorescence microscopy was used to assess changes in keratocyte morphology, as well as to quantify the dynamic traction stresses exerted by cells under different experimental conditions. In other experiments, keratocytes were fixed after 5 days of culture and stained for markers of both contractility and myofibroblastic activation. Treatment with TGF-β1 elicited distinct phenotypes on substrata of different stiffnesses. Cells on soft (1 kPa) gels formed fewer stress fibers and retained a more dendritic morphology, indicative of a quiescent keratocyte phenotype. Keratocytes cultured on stiff (10 kPa) gels or collagen-coated glass coverslips, however, had broad morphologies, formed abundant stress fibers, exhibited greater levels of α-smooth muscle actin (α-SMA) expression, and exerted larger traction forces. Confocal images of phospho-myosin light chain (pMLC) immunofluorescence, moreover, revealed stiffness-dependent differences in the subcellular distribution of actomyosin contractility, with pMLC localized at the tips of thin cellular processes in mechanically quiescent cells. Importantly, keratocytes cultured in the absence of TGF-β1 showed no stiffness-dependent differences in α-SMA immunofluorescence, suggesting that a stiff microenvironment alone is insufficient to induce myofibroblastic activation. Taken together, these data suggest that changes in ECM stiffness can modulate the morphology, cytoskeletal organization, and subcellular pattern of force generation in corneal keratocytes treated with TGF-β1.
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Affiliation(s)
- Daniel P Maruri
- Department of Bioengineering, University of Texas at Dallas, Richardson, Texas
| | - Miguel Miron-Mendoza
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Pouriska B Kivanany
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Joshua M Hack
- Department of Bioengineering, University of Texas at Dallas, Richardson, Texas
| | - David W Schmidtke
- Department of Bioengineering, University of Texas at Dallas, Richardson, Texas; Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Texas
| | - W Matthew Petroll
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Victor D Varner
- Department of Bioengineering, University of Texas at Dallas, Richardson, Texas; Department of Surgery, University of Texas Southwestern Medical Center, Dallas, Texas.
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21
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Coupling of Fibrin Reorganization and Fibronectin Patterning by Corneal Fibroblasts in Response to PDGF BB and TGFβ1. Bioengineering (Basel) 2020; 7:bioengineering7030089. [PMID: 32784578 PMCID: PMC7552779 DOI: 10.3390/bioengineering7030089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/02/2020] [Accepted: 08/05/2020] [Indexed: 11/17/2022] Open
Abstract
We previously reported that corneal fibroblasts within 3D fibrin matrices secrete, bind, and organize fibronectin into tracks that facilitate cell spreading and migration. Other cells use these fibronectin tracks as conduits, which leads to the development of an interconnected cell/fibronectin network. In this study, we investigate how cell-induced reorganization of fibrin correlates with fibronectin track formation in response to two growth factors present during wound healing: PDGF BB, which stimulates cell spreading and migration; and TGFβ1, which stimulates cellular contraction and myofibroblast transformation. Both PDGF BB and TGFβ1 stimulated global fibrin matrix contraction (p < 0.005); however, the cell and matrix patterning were different. We found that, during PDGF BB-induced cell spreading, fibronectin was organized simultaneously with the generation of tractional forces at the leading edge of pseudopodia. Over time this led to the formation of an interconnected network consisting of cells, fibronectin and compacted fibrin tracks. Following culture in TGFβ1, cells were less motile, produced significant local fibrin reorganization, and formed fewer cellular connections as compared to PDGF BB (p < 0.005). Although bands of compacted fibrin tracks developed in between neighboring cells, fibronectin labeling was not generally present along these tracks, and the correlation between fibrin and fibronectin labeling was significantly less than that observed in PDGF BB (p < 0.001). Taken together, our results show that cell-induced extracellular matrix (ECM) reorganization can occur independently from fibronectin patterning. Nonetheless, both events seem to be coordinated, as corneal fibroblasts in PDGF BB secrete and organize fibronectin as they preferentially spread along compacted fibrin tracks between cells, producing an interconnected network in which cells, fibronectin and compacted fibrin tracks are highly correlated. This mechanism of patterning could contribute to the formation of organized cellular networks that have been observed following corneal injury and refractive surgery.
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22
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Kafarnik C, McClellan A, Dziasko M, Daniels JT, Guest DJ. Canine Corneal Stromal Cells Have Multipotent Mesenchymal Stromal Cell Properties In Vitro. Stem Cells Dev 2020; 29:425-439. [PMID: 31973649 DOI: 10.1089/scd.2019.0163] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The objective of this study was to determine whether corneal stromal cells (CSCs) from the limbal and central corneal stroma in dogs have multipotent mesenchymal stem/stromal cell (MSC) properties, and whether this cell population can be differentiated into keratocyte-like cells (KDCs). Normal, donated, mesocephalic dog corneas were used to isolate CSC in vitro. Immunohistochemistry demonstrated a distinct population of CD90 expressing cells in the anterior stroma throughout the limbal and central cornea. CSC could be cultured from both the limbal and central cornea and the culture kinetics showed a progenitor cell profile. The CSC expressed stem cell markers CD90, CD73, CD105, N-cadherin, and Pax6, while CD34 was negative. Limbal and central CSC differentiated into osteoblasts, chondrocytes, and adipocytes confirming their multipotency. Coculturing allogeneic peripheral blood mononuclear cells (PBMCs) with limbal CSCs did not affect baseline PBMC proliferation indicating a degree of innate immune privilege. Limbal CSC could be differentiated into KDCs that expressed Keratocan, Lumican, and ALDH1A3 and downregulated Pax6 and N-cadherin. In conclusion, canine CSCs have multipotent MSC properties similarly described in humans and could serve as a source of cells for cell therapy and studying corneal diseases.
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Affiliation(s)
- Christiane Kafarnik
- Centre for Preventive Medicine, Animal Health Trust, Newmarket, United Kingdom.,Rescue, Repair and Regeneration Theme, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Alyce McClellan
- Centre for Preventive Medicine, Animal Health Trust, Newmarket, United Kingdom
| | - Marc Dziasko
- Rescue, Repair and Regeneration Theme, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Julie T Daniels
- Rescue, Repair and Regeneration Theme, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Deborah J Guest
- Centre for Preventive Medicine, Animal Health Trust, Newmarket, United Kingdom
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Han KY, Chang JH, Azar DT. MMP14-Containing Exosomes Cleave VEGFR1 and Promote VEGFA-Induced Migration and Proliferation of Vascular Endothelial Cells. Invest Ophthalmol Vis Sci 2019; 60:2321-2329. [PMID: 31117124 PMCID: PMC6532701 DOI: 10.1167/iovs.18-26277] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 04/17/2019] [Indexed: 12/17/2022] Open
Abstract
Purpose Investigate the impact matrix metalloproteinase 14 (MMP14) delivered via exosomes produced by corneal fibroblasts on vascular endothelial growth factor receptor 1 (VEGFR1) cleavage on endothelial cells, and other key processes of angiogenesis. Methods Proteolysis of VEGFR1 and R2 by the catalytic domain of MMP14 was investigated via immunocytochemistry with anti-VEGFR1, anti-VEGFR2, and anti-MMP14 antibodies. Exosomes were isolated via precipitation and serial ultracentrifugation from wild-type (WT) and MMP14 exon4-deficient corneal fibroblasts. Transmission electron microscopy and nanotracking analysis were used to characterize the isolated exosomes. The presence of MMP14 in exosomes from WT fibroblasts was confirmed by Western blotting. VEGFR1 cleavage upon treatment with WT-derived exosomes, Δexon4-derived exosomes, or the pan-MMP inhibitor GM60001 was examined via in vitro proteolysis analysis using recombinant mouse (rm) VEGFR1/R2. Endothelial cell migration and proliferation were investigated using a Boyden chamber assay and BrdU incorporation, respectively. Results WT-derived exosomes specifically cleaved rmVEGFR1 in vitro, whereas Δexon4-derived exosomes did not. Treatment with the pan-MMP inhibitor GM6001 effectively inhibited VEGFR1 cleavage by WT-derived exosomes, confirming the role of MMP14 in this cleavage. WT-derived exosomes induced greater endothelial cell migration (P < 0.01) and proliferation (P < 0.5) compared to Δexon4-derived exosomes. Conclusions MMP14-containing exosomes may be involved in the regulation of corneal neovascularization through degradation of VEGFR1 and VEGFA-induced endothelial cell proliferation and migration.
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Affiliation(s)
- Kyu-Yeon Han
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois-Chicago, Chicago, Illinois, United States
| | - Jin-Hong Chang
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois-Chicago, Chicago, Illinois, United States
| | - Dimitri T. Azar
- Department of Ophthalmology and Visual Sciences, Illinois Eye and Ear Infirmary, College of Medicine, University of Illinois-Chicago, Chicago, Illinois, United States
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Kim H, Park MN, Kim J, Jang J, Kim HK, Cho DW. Characterization of cornea-specific bioink: high transparency, improved in vivo safety. J Tissue Eng 2019; 10:2041731418823382. [PMID: 30719272 PMCID: PMC6348552 DOI: 10.1177/2041731418823382] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 12/16/2018] [Indexed: 12/22/2022] Open
Abstract
Corneal transplantation is a typical surgical procedure for severe corneal diseases. However, the waiting time for a donor cornea has gradually increased due to a decrease in supply caused by an aging population and increased cases of laser-based surgeries. Artificial corneas were developed to meet the increase in demand; however, these approaches have suffered from material deterioration resulted by the limited tissue integration. Here, we introduce a cornea-derived decellularized extracellular matrix (Co-dECM) as a bioink for corneal regeneration. The developed Co-dECM bioink had similar quantitative measurement results for collagen and GAGs compared with that of the native cornea and also had the proper transparency for vision. The differentiation potential of human turbinate-derived mesenchymal stem cells (hTMSCs) to a keratocyte lineage was only observed in the Co-dECM group. Moreover, the developed bioink did not have any cytotoxic effect on encapsulated cells for three-dimensional (3D) culture and has great biocompatibility evident by the xeno-implantation of the Co-dECM gel into mice and rabbits for two and one month, respectively. An in vivo safety similar to clinical-grade collagen was seen with the Co-dECM, which helped to maintain the keratocyte-specific characteristics in vivo, compared with collagen. Taken together, the Co-dECM bioink has the potential to be used in various types of corneal diseases based on its corneal-specific ability and design flexibility through 3D cell printing technology.
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Affiliation(s)
- Hyeonji Kim
- Department of Mechanical Engineering and Center for Rapid Prototyping-based 3D Tissue/Organ Printing, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Moon-Nyeo Park
- College of Korean Medicines, Kyung Hee University, Seoul, Republic of Korea
| | - Jisoo Kim
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Jinah Jang
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Republic of Korea
- Department of Creative IT Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Hong-Kyun Kim
- Department of Ophthalmology, Kyungpook National University School of Medicine, Daegu, Republic of Korea
| | - Dong-Woo Cho
- Department of Mechanical Engineering and Center for Rapid Prototyping-based 3D Tissue/Organ Printing, Pohang University of Science and Technology, Pohang, Republic of Korea
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Fernández-Pérez J, Ahearne M. Influence of Biochemical Cues in Human Corneal Stromal Cell Phenotype. Curr Eye Res 2018; 44:135-146. [PMID: 30335528 DOI: 10.1080/02713683.2018.1536216] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
PURPOSE To identify biochemical cues that could promote a keratocyte-like phenotype in human corneal stromal cells that had become fibroblastic when expanded in serum-supplemented media while also examining the effect on cell proliferation and migration. METHODS Proliferation was assessed by PrestoBlue™, morphology was monitored by phase contrast microscopy, phenotype was analyzed by real-time polymerase chain reaction (qPCR), immunochemistry and flow cytometry, and migration was studied with a scratch assay. RESULTS Ascorbic Acid (AA), Retinoic Acid (RA), Insulin-Transferrin-Selenium (ITS), Insulin-like Growth Factor 1 (IGF-1) and 3-isobutyl-1-methylxanthine (IBMX) promoted a dendritic morphology, increased the expression of keratocyte markers, such as keratocan, aldehyde dehydrogenase 3 family member A1 (ALDH3A1) and CD34, and prevented myofibroblast differentiation, while in some cases increasing proliferation. Transforming Growth Factor beta 1 (TGF-β1) and 3 (TGF-β3) promoted the differentiation toward myofibroblasts, with increased expression of α-SMA. Fibroblast Growth Factor 2 (FGF-2) supported a fibroblastic phenotype while Platelet-Derived Growth Factor Homodimer B (PDGF-BB) induced a pro-migratory fibroblastic phenotype. A combination of all the pro-keratocyte factors was also compared to the serum-free only, which significantly increased CD34 and keratocan expression. CONCLUSIONS Partially recovery towards a quiescent keratocyte-like phenotype was achieved by the removal of serum and the addition of AA, IGF-1, RA, ITS and IBMX to a basal medium. These findings can be used to develop cell-based corneal therapies and to study corneal diseases in vitro.
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Affiliation(s)
- Julia Fernández-Pérez
- a Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin , University of Dublin , Dublin , Ireland.,b Trinity Centre for Bioengineering, Trinity Biomedical Science Institute, Trinity College Dublin , University of Dublin , Dublin , Ireland
| | - Mark Ahearne
- a Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin , University of Dublin , Dublin , Ireland.,b Trinity Centre for Bioengineering, Trinity Biomedical Science Institute, Trinity College Dublin , University of Dublin , Dublin , Ireland
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Miron-Mendoza M, Graham E, Manohar S, Petroll WM. Fibroblast-fibronectin patterning and network formation in 3D fibrin matrices. Matrix Biol 2017; 64:69-80. [PMID: 28602859 PMCID: PMC5705415 DOI: 10.1016/j.matbio.2017.06.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 05/26/2017] [Accepted: 06/01/2017] [Indexed: 12/25/2022]
Abstract
PURPOSE We previously reported that fibroblasts migrating within 3-D collagen matrices move independently, whereas fibroblasts within 3-D fibrin matrices form an interconnected network. Similar networks have been identified previously during in vivo corneal wound healing. In this study, we investigate the role of fibronectin in mediating this mechanism of collective cell spreading, migration and patterning. METHODS To assess cell spreading, corneal fibroblasts were plated within fibrillar collagen or fibrin matrices. To assess migration, compacted cell-populated collagen matrices were nested inside cell-free fibrin matrices. Constructs were cultured in serum-free media containing PDGF, with or without RGD peptide, anti-α5 or anti-fibronectin blocking antibodies. In some experiments, LifeAct and fluorescent fibronectin were used to allow dynamic assessment of cell-induced fibronectin reorganization. 3-D and 4-D imaging were used to assess cell mechanical behavior, connectivity, F-actin, α5 integrin and fibronectin organization. RESULTS Corneal fibroblasts within 3-D fibrin matrices formed an interconnected network that was lined with cell-secreted fibronectin. Live cell imaging demonstrated that fibronectin tracks were formed at the leading edge of spreading and migrating cells. Furthermore, fibroblasts preferentially migrated through fibronectin tracks laid down by other cells. Interfering with cell-fibronectin binding with RGD, anti α5 integrin or anti fibronectin antibodies inhibited cell spreading and migration through fibrin, but did not affect cell behavior in collagen. CONCLUSIONS In this study, a novel mode of cell patterning was identified in which corneal fibroblasts secrete and attach to fibronectin via α5β1 integrin to facilitate spreading and migration within 3-D fibrin matrices, resulting in the formation of localized fibronectin tracks. Other cells use these fibronectin tracks as conduits, resulting in an interconnected cell-fibronectin network.
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Affiliation(s)
- Miguel Miron-Mendoza
- Department of Ophthalmology, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9057, United States
| | - Eric Graham
- Department of Ophthalmology, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9057, United States
| | - Sujal Manohar
- Department of Ophthalmology, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9057, United States
| | - W Matthew Petroll
- Department of Ophthalmology, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9057, United States.
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Fernandes-Cunha GM, Lee HJ, Kumar A, Kreymerman A, Heilshorn S, Myung D. Immobilization of Growth Factors to Collagen Surfaces Using Pulsed Visible Light. Biomacromolecules 2017; 18:3185-3196. [PMID: 28799757 DOI: 10.1021/acs.biomac.7b00838] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
In the treatment of traumatic injuries, burns, and ulcers of the eye, inadequate epithelial tissue healing remains a major challenge. Wound healing is a complex process involving the temporal and spatial interplay between cells and their extracellular milieu. It can be impaired by a variety of causes including infection, poor circulation, loss of critical cells, and/or proteins, and a deficiency in normal neural signaling (e.g., neurotrophic ulcers). Ocular anatomy is particularly vulnerable to lasting morbidity from delayed healing, whether it be scarring or perforation of the cornea, destruction of the conjunctival mucous membrane, or cicatricial changes to the eyelids and surrounding skin. Therefore, there is a major clinical need for new modalities for controlling and accelerating wound healing, particularly in the eye. Collagen matrices have long been explored as scaffolds to support cell growth as both two-dimensional coatings and substrates, as well as three-dimensional matrices. Meanwhile, the immobilization of growth factors to various substrates has also been extensively studied as a way to promote enhanced cellular adhesion and proliferation. Herein we present a new strategy for photochemically immobilizing growth factors to collagen using riboflavin as a photosensitizer and exposure to visible light (∼458 nm). Epidermal growth factor (EGF) was successfully bound to collagen-coated surfaces as well as directly to endogenous collagen from porcine corneas. The initial concentration of riboflavin and EGF as well as the blue light exposure time were keys to the successful binding of growth factors to these surfaces. The photocrosslinking reaction increased EGF residence time on collagen surfaces over 7 days. EGF activity was maintained after the photocrosslinking reaction with a short duration of pulsed blue light exposure. Bound EGF accelerated in vitro corneal epithelial cell proliferation and migration and maintained normal cell phenotype. Additionally, the treated surfaces were cytocompatible, and the photocrosslinking reaction was proven to be safe, preserving nearly 100% cell viability. These results suggest that this general approach is safe and versatile may be used for targeting and immobilizing bioactive factors onto collagen matrices in a variety of applications, including in the presence of live, seeded cells or in vivo onto endogenous extracellular matrix collagen.
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Affiliation(s)
| | - Hyun Jong Lee
- Byers Eye Institute at Stanford University School of Medicine , Palo Alto, California 94303, United States
| | - Alisha Kumar
- Byers Eye Institute at Stanford University School of Medicine , Palo Alto, California 94303, United States
| | - Alexander Kreymerman
- Byers Eye Institute at Stanford University School of Medicine , Palo Alto, California 94303, United States
| | - Sarah Heilshorn
- Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States
| | - David Myung
- Byers Eye Institute at Stanford University School of Medicine , Palo Alto, California 94303, United States.,VA Palo Alto Health Care System , Palo Alto, CA 94304, United States
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Gallego‐Muñoz P, Ibares‐Frías L, Garrote JA, Valsero‐Blanco MC, Cantalapiedra‐Rodríguez R, Merayo‐Lloves J, Carmen Martínez‐García M. Human corneal fibroblast migration and extracellular matrix synthesis during stromal repair: Role played by platelet‐derived growth factor‐BB, basic fibroblast growth factor, and transforming growth factor‐β1. J Tissue Eng Regen Med 2017; 12:e737-e746. [DOI: 10.1002/term.2360] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 10/17/2016] [Accepted: 11/09/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Patricia Gallego‐Muñoz
- Departamento de Biología Celular, Histología y Farmacología. Facultad de Medicina. Grupo de Investigación Reconocido: Técnicas Ópticas para el DiagnósticoUniversidad de Valladolid Valladolid Spain
| | - Lucía Ibares‐Frías
- Departamento de Biología Celular, Histología y Farmacología. Facultad de Medicina. Grupo de Investigación Reconocido: Técnicas Ópticas para el DiagnósticoUniversidad de Valladolid Valladolid Spain
- Servicio de OftalmologíaHospital Clínico Universitario de Valladolid Valladolid Spain
| | - José A. Garrote
- Servicio de Análisis Clínicos. Laboratorio de GenéticaHospital Universitario Rio Hortega de Valladolid Valladolid Spain
| | | | - Roberto Cantalapiedra‐Rodríguez
- Departamento de Biología Celular, Histología y Farmacología. Facultad de Medicina. Grupo de Investigación Reconocido: Técnicas Ópticas para el DiagnósticoUniversidad de Valladolid Valladolid Spain
| | | | - M. Carmen Martínez‐García
- Departamento de Biología Celular, Histología y Farmacología. Facultad de Medicina. Grupo de Investigación Reconocido: Técnicas Ópticas para el DiagnósticoUniversidad de Valladolid Valladolid Spain
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Gallego-Muñoz P, Ibares-Frías L, Valsero-Blanco MC, Cantalapiedra-Rodriguez R, Merayo-Lloves J, Martínez-García MC. Effects of TGFβ1, PDGF-BB, and bFGF, on human corneal fibroblasts proliferation and differentiation during stromal repair. Cytokine 2017; 96:94-101. [PMID: 28390267 DOI: 10.1016/j.cyto.2017.03.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 02/22/2017] [Accepted: 03/31/2017] [Indexed: 12/27/2022]
Abstract
In an effort to improve the regenerative nature of corneal repair, this study reports the use of an in vitro human corneal fibroblasts (HCFs) wound model after treatment with three of the main growth factors (GFs) involved in corneal healing: transforming growth factor beta 1 (TGFβ1), platelet-derived growth factor BB-isoform (PDGF-BB), and basic fibroblast growth factor (bFGF) in order to delve in cell proliferation and differentiation processes. HCFs were mechanically wounded. The individual effect of TGFβ1, PDGF-BB, and bFGF on cell proliferation and differentiation during the repair process was studied at different time points until wound closure. Wound dimensions and morphological changes were evaluated by microscopy. Cell proliferation and myofibroblast differentiation were analyzed by immunofluorescence cytochemistry. Changes in cell morphology were apparent at Day 4. PDGF-BB- and bFGF-treated cells had fibroblast-like morphology. TGFβ1 stimulated proliferation in the wound edge and surrounding area, induced myofibroblast differentiation and inhibited cellular migration. PDGF-BB induced rapid wound closure due to proliferation, high motility, and late myofibroblast differentiation. The time course of closure induced by bFGF was similar to that for PDGF-BB, but was mostly due to proliferation in the wound area, and inhibited myofibroblast differentiation. Each of the GFs induced increases in responses promoting stromal repair differently. This study provides insight regarding how to optimize the outcome of stromal repair following corneal injury.
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Affiliation(s)
- Patricia Gallego-Muñoz
- Departamento de Biología Celular, Histología y Farmacología, Facultad de Medicina, Grupo de Investigación Reconocido: Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain.
| | - Lucía Ibares-Frías
- Departamento de Biología Celular, Histología y Farmacología, Facultad de Medicina, Grupo de Investigación Reconocido: Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain; Servicio de Oftalmología, Hospital Clínico Universitario de Valladolid, Valladolid, Spain
| | | | - Roberto Cantalapiedra-Rodriguez
- Departamento de Biología Celular, Histología y Farmacología, Facultad de Medicina, Grupo de Investigación Reconocido: Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain
| | - Jesús Merayo-Lloves
- Instituto Oftalmológico Fernández-Vega, Universidad de Oviedo, Oviedo, Spain
| | - M Carmen Martínez-García
- Departamento de Biología Celular, Histología y Farmacología, Facultad de Medicina, Grupo de Investigación Reconocido: Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain
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Sidney LE, Hopkinson A. 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. J Tissue Eng Regen Med 2017; 12:e203-e215. [PMID: 27685949 DOI: 10.1002/term.2316] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 07/28/2016] [Accepted: 09/26/2016] [Indexed: 01/07/2023]
Abstract
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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Affiliation(s)
- Laura E Sidney
- Academic Ophthalmology, Division of Clinical Neuroscience, Queen's Medical Centre Campus, University of Nottingham, UK
| | - Andrew Hopkinson
- Academic Ophthalmology, Division of Clinical Neuroscience, Queen's Medical Centre Campus, University of Nottingham, UK
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31
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Feng X, Pi L, Sriram S, Schultz GS, Gibson DJ. Connective tissue growth factor is not necessary for haze formation in excimer laser wounded mouse corneas. PLoS One 2017; 12:e0172304. [PMID: 28207886 PMCID: PMC5313228 DOI: 10.1371/journal.pone.0172304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 02/02/2017] [Indexed: 11/19/2022] Open
Abstract
We sought to determine if connective tissue growth factor (CTGF) is necessary for the formation of corneal haze after corneal injury. Mice with post-natal, tamoxifen-induced, knockout of CTGF were subjected to excimer laser phototherapeutic keratectomy (PTK) and the corneas were allowed to heal. The extent of scaring was observed in non-induced mice, heterozygotes, and full homozygous knockout mice and quantified by macrophotography. The eyes from these mice were collected after euthanization for re-genotyping to control for possible Cre-mosaicism. Primary corneal fibroblasts from CTGF knockout corneas were established in a gel plug assay. The plug was removed, simulating an injury, and the rate of hole closure and the capacity for these cells to form light reflecting cells in response to CTGF and platelet-derived growth factor B (PDGF-B) were tested and compared to wild-type cells. We found that independent of genotype, each group of mice was still capable of forming light reflecting haze in the cornea after laser ablation (p = 0.40). Results from the gel plug closure rate in primary cell cultures of knockout cells were not statistically different from serum starved wild-type cells, independent of treatment. Compared to the serum starved wild-type cells, stimulation with PDGF-BB significantly increased the KO cell culture’s light reflection (p = 0.03). Most interestingly, both reflective cultures were positive for α-SMA, but the cellular morphology and levels of α-SMA were distinct and not in proportion to the light reflection seen. This new work demonstrates that corneas without CTGF can still form sub-epithelial haze, and that the light reflecting phenotype can be reproduced in culture. These data support the possibilities of growth factor redundancy and that multiple pro-haze pathways exist.
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Affiliation(s)
- Xiaodi Feng
- Institute of Wound Research, University of Florida, Gainesville, Florida, United States of America
| | - Liya Pi
- Department of Pediatrics, University of Florida, Gainesville, Florida, United States of America
| | - Sriniwas Sriram
- Department of Biomedical Engineering, University of Florida, Gainesville, Florida, United States of America
| | - Gregory S. Schultz
- Institute of Wound Research, University of Florida, Gainesville, Florida, United States of America
| | - Daniel J. Gibson
- Institute of Wound Research, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
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Lynch AP, Ahearne M. Retinoic Acid Enhances the Differentiation of Adipose-Derived Stem Cells to Keratocytes In Vitro. Transl Vis Sci Technol 2017; 6:6. [PMID: 28138416 PMCID: PMC5270625 DOI: 10.1167/tvst.6.1.6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 12/05/2016] [Indexed: 12/13/2022] Open
Abstract
Purpose All-trans retinoic acid (RA) supplementation was investigated as a method of enhancing the differentiation of human adipose-derived stem cells (ASCs) to corneal keratocytes in vitro, in combination with a chemically defined serum-free medium. Methods Adipose-derived stem cells were cultured in monolayer and supplemented with 0.1, 1, or 10 μM RA for 14 days. The effects of RA on cell proliferation, migration, and extracellular matrix (ECM) accumulation were evaluated. In addition, the expression of phenotypic keratocyte markers was examined by reverse transcription polymerase chain reaction (PCR), immunocytochemistry, and Western blotting. Results Adipose-derived stem cells cultured with RA showed improved cell proliferation and ECM production. In addition, RA enhanced the expression of keratocyte-specific markers, keratocan, aldehyde dehydrogenase 3A1, lumican, and decorin, when compared to serum-free media alone. Furthermore, the presence of RA increased the amount of collagen type I while reducing the expression of fibrotic marker, α-smooth muscle actin. Conclusions These findings indicate that RA is a useful supplement for promoting a keratocyte phenotype in ASC. Translational Relevance This study is particularly important for the generation of biological corneal substitutes and next generation cell based therapies for corneal conditions.
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Affiliation(s)
- Amy P Lynch
- Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, University of Dublin, Dublin, Ireland, ; Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin, University of Dublin, Dublin, Ireland
| | - Mark Ahearne
- Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, University of Dublin, Dublin, Ireland, ; Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin, University of Dublin, Dublin, Ireland
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33
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Lynch AP, O'Sullivan F, Ahearne M. The effect of growth factor supplementation on corneal stromal cell phenotype in vitro using a serum-free media. Exp Eye Res 2016; 151:26-37. [PMID: 27456135 DOI: 10.1016/j.exer.2016.07.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 04/07/2016] [Accepted: 07/21/2016] [Indexed: 12/13/2022]
Abstract
In order to expand cells quickly and in high numbers for corneal tissue engineering applications corneal stromal cells, or keratocytes, are often cultured in the presence of serum. However, keratocytes become fibroblastic when exposed to serum leading to a downregulation of corneal stromal specific markers. The purpose of this current study was to determine if corneal stromal cells, made fibroblastic by serum, could display native quiescent keratocyte characteristics when cultured under serum-free conditions supplemented by different growth factors. Markers specific to a native keratocyte phenotype such as keratocan and aldehyde dehydrogenase 3A1 (ALDH3A1) and those specific to a fibrotic phenotype such as α-smooth muscle actin (αSMA) and collagen type III were examined. Cells were cultured in monolayer, self-assembled pellets or collagen hydrogels. Growth factors known to modulate keratocyte phenotype were chosen to supplement the serum free media, specifically insulin-like growth factor 1 (IGF-1) and transforming growth factor beta 1 and 3 (Tβ1 and Tβ3). The effects of serum-free media, growth factors and culture system on cell proliferation and morphology and extracellular matrix (ECM) synthesis were evaluated. The expression of keratocyte markers was evaluated by real-time PCR, immunofluorescent staining and western blotting. In addition, cell migration was tested using scratch assays. When serum was removed from the cells they displayed a reduction in proliferation and ECM synthesis (not significant), in addition to a significant decrease in migratory capacity (p < 0.05). Serum-free media promoted increased expression of keratocan (130.68 ± 47.44-fold increase; p < 0.05) and collagen type I (15.58 ± 9.49-fold increase; p < 0.05). However, there was no significant change in ALDH3A1 and αSMA expression, while collagen type III expression was significantly increased (44.66 ± 25.61-fold increase; p < 0.05). In addition, cells retained an elongated fibroblastic morphology. In monolayer, the addition of Tβ1 and Tβ3 to serum free media resulted in reduced expression of keratocan, ALDH3A1 and collagen type I and III, increased expression of αSMA (p < 0.05) and an increase in cell proliferation and ECM synthesis. Pellet cultured cells demonstrated a significant increase in ALDH3A1 and collagen type I over 14 days relative to day 5 (p < 0.05), however the expression of fibrotic markers was also enhanced. Cells in collagen hydrogels did not increase expression of keratocyte markers in serum free conditions and underwent contraction in Tβ1 and Tβ3 supplemented media. These results demonstrate that corneal fibroblasts only partially express the phenotypic characteristics of keratocytes when cultured in serum-free medium. While growth factors did not significantly enhance this phenotype, it appears that pellet or self-assembled culture could be more beneficial to promoting a keratocyte phenotype.
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Affiliation(s)
- Amy P Lynch
- Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Pearse Street, Dublin 2, Ireland; Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin, Ireland
| | - Finbarr O'Sullivan
- National Institute for Cellular Biotechnology, Dublin City University, Dublin, Ireland
| | - Mark Ahearne
- Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Pearse Street, Dublin 2, Ireland; Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin, Ireland.
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Ko P, Kim D, You E, Jung J, Oh S, Kim J, Lee KH, Rhee S. Extracellular Matrix Rigidity-dependent Sphingosine-1-phosphate Secretion Regulates Metastatic Cancer Cell Invasion and Adhesion. Sci Rep 2016; 6:21564. [PMID: 26877098 PMCID: PMC4753492 DOI: 10.1038/srep21564] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 01/27/2016] [Indexed: 12/14/2022] Open
Abstract
Dynamic interaction between cancer cells and the surrounding microenvironment is critical for cancer progression via changes in cellular behavior including alteration of secreted molecules. However, the molecular mechanisms underlying the influence exerted by the cancer microenvironment on secretion of molecules during cancer progression remain largely unknown. In this study, we report that secretion of spingsine-1-phosphate (S1P) and its regulator, SphK1 expression is dependent of the substrate rigidity, which is critical for the balance between cancer cell invasion and adhesion. Conditioned media (CM) of MDA-MB-231, an aggressive breast cancer cell obtained from soft substrate (~0.5 kPa) induced chemo-attractive invasion, while CM obtained from stiff substrate (~2.5 kPa) increased cell adhesion instead. We found that the expression of SphK1 is upregulated in the stiff substrate, resulting in an increase in S1P levels in the CM. We also found that upregulation of SphK1 expression in the stiff substrate is dominant in metastatic cancer cells but not in primary cancer cells. These results suggest that alterations in the mechanical environment of the ECM surrounding the tumor cells actively regulate cellular properties such as secretion, which in turn, may contribute to cancer progression.
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Affiliation(s)
- Panseon Ko
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Daehwan Kim
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Eunae You
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Jangho Jung
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Somi Oh
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Jaehyun Kim
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Kwang-Ho Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Sangmyung Rhee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
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Shankar SP, Griffith M, Forrester JV, Kuffová L. Dendritic cells and the extracellular matrix: A challenge for maintaining tolerance/homeostasis. World J Immunol 2015; 5:113-130. [DOI: 10.5411/wji.v5.i3.113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/18/2015] [Accepted: 11/11/2015] [Indexed: 02/05/2023] Open
Abstract
The importance of the extracellular matrix (ECM) in contributing to structural, mechanical, functional and tissue-specific features in the body is well appreciated. While the ECM was previously considered to be a passive bystander, it is now evident that it plays active, dynamic and flexible roles in shaping cell survival, differentiation, migration and death to varying extents depending on the specific site in the body. Dendritic cells (DCs) are recognized as potent antigen presenting cells present in many tissues and in blood, continuously scrutinizing the microenvironment for antigens and mounting local and systemic host responses against harmful agents. DCs also play pivotal roles in maintaining homeostasis to harmless self-antigens, critical for preventing autoimmunity. What is less understood are the complex interactions between DCs and the ECM in maintaining this balance between steady-state tissue residence and DC activation during inflammation. DCs are finely tuned to inflammation-induced variations in fragment length, accessible epitopes and post-translational modifications of individual ECM components and correspondingly interpret these changes appropriately by adjusting their profiles of cognate binding receptors and downstream immune activation. The successful design and composition of novel ECM-based mimetics in regenerative medicine and other applications rely on our improved understanding of DC-ECM interplay in homeostasis and the challenges involved in maintaining it.
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36
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Sidney LE, Branch MJ, Dua HS, Hopkinson A. Effect of culture medium on propagation and phenotype of corneal stroma-derived stem cells. Cytotherapy 2015; 17:1706-22. [PMID: 26454751 DOI: 10.1016/j.jcyt.2015.08.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 08/06/2015] [Accepted: 08/19/2015] [Indexed: 12/12/2022]
Abstract
BACKGROUND AIMS The limbal area of the corneal stroma has been identified as a source of mesenchymal-like stem cells, which have potential for exploitation as a cell therapy. However, the optimal culture conditions are disputed and few direct media comparisons have been performed. In this report, we evaluated several media types to identify the optimal for inducing an in vitro stem cell phenotype. METHODS Primary human corneal stroma-derived stem cells (CSSCs) were extracted from corneoscleral rims. Culture in seven different media types was compared: Dulbecco's modified Eagle's medium (DMEM) with 10% fetal bovine serum (FBS); M199 with 20% FBS; DMEM-F12 with 20% serum replacement, basic fibroblast growth factor and leukemia inhibitory factor (SCM); endothelial growth medium (EGM); semi-solid MethoCult; serum-free keratinocyte medium (K-SFM); and StemPro-34. Effects on proliferation, morphology, protein and messenger RNA expression were evaluated. RESULTS All media supported proliferation of CSSCs with the exception of K-SFM and StemPro-34. Morphology differed between media: DMEM produced large cells, whereas EGM produced very small cells. Culture in M199 produced a typical mesenchymal stromal cell phenotype with high expression of CD105, CD90 and CD73 but not CD34. Culture in SCM produced a phenotype more reminiscent of a progenitor cell type with expression of CD34, ABCG2, SSEA-4 and PAX6. CONCLUSIONS Culture medium can significantly influence CSSC phenotype. SCM produced a cell phenotype closest to that of a pluripotent stem cell, and we consider it to be the most appropriate for development as a clinical-grade medium for the production of CSSC phenotypes suitable for cell therapy.
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Affiliation(s)
- Laura E Sidney
- Academic Ophthalmology, Division of Clinical Neuroscience, Queen's Medical Centre Campus, University of Nottingham, Nottingham, United Kingdom.
| | - Matthew J Branch
- Academic Ophthalmology, Division of Clinical Neuroscience, Queen's Medical Centre Campus, University of Nottingham, Nottingham, United Kingdom
| | - Harminder S Dua
- Academic Ophthalmology, Division of Clinical Neuroscience, Queen's Medical Centre Campus, University of Nottingham, Nottingham, United Kingdom
| | - Andrew Hopkinson
- Academic Ophthalmology, Division of Clinical Neuroscience, Queen's Medical Centre Campus, University of Nottingham, Nottingham, United Kingdom
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Miotto M, Gouveia RM, Connon CJ. Peptide Amphiphiles in Corneal Tissue Engineering. J Funct Biomater 2015; 6:687-707. [PMID: 26258796 PMCID: PMC4598678 DOI: 10.3390/jfb6030687] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 07/29/2015] [Accepted: 08/03/2015] [Indexed: 12/22/2022] Open
Abstract
The increasing interest in effort towards creating alternative therapies have led to exciting breakthroughs in the attempt to bio-fabricate and engineer live tissues. This has been particularly evident in the development of new approaches applied to reconstruct corneal tissue. The need for tissue-engineered corneas is largely a response to the shortage of donor tissue and the lack of suitable alternative biological scaffolds preventing the treatment of millions of blind people worldwide. This review is focused on recent developments in corneal tissue engineering, specifically on the use of self-assembling peptide amphiphiles for this purpose. Recently, peptide amphiphiles have generated great interest as therapeutic molecules, both in vitro and in vivo. Here we introduce this rapidly developing field, and examine innovative applications of peptide amphiphiles to create natural bio-prosthetic corneal tissue in vitro. The advantages of peptide amphiphiles over other biomaterials, namely their wide range of functions and applications, versatility, and transferability are also discussed to better understand how these fascinating molecules can help solve current challenges in corneal regeneration.
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Affiliation(s)
- Martina Miotto
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK.
| | - Ricardo M Gouveia
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK.
| | - Che J Connon
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle upon Tyne NE1 3BZ, UK.
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Ahearne M, Lynch AP. Early Observation of Extracellular Matrix-Derived Hydrogels for Corneal Stroma Regeneration. Tissue Eng Part C Methods 2015; 21:1059-69. [PMID: 25951055 DOI: 10.1089/ten.tec.2015.0008] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A lack of healthy transplantable tissue to treat corneal blindness has led researchers to investigate the development and application of different scaffold materials for corneal tissue engineering and regeneration. In this study, hydrogels fabricated from decellularized corneal extracellular matrix were developed as a new approach to corneal stromal tissue regeneration. Porcine corneas were decellularized using a technique that combined freeze-thaw cycles with a nuclease treatment. The corneas were then freeze-dried, milled, and digested in an acidic pepsin solution that was used to form a hydrogel after adjusting the pH and gelation temperature. The resultant corneal matrix hydrogels (CMHs) were seeded with human corneal stromal cells and cultured for several days. When compared to collagens hydrogels, CMHs had superior optical transparency, similar mechanical properties, and were better able to retain the stromal cells native keratocyte phenotype. The CMHs also supported cell viability and proliferation and contained sulfated glycosaminoglycan, a vital constituent, for maintaining corneal transparency. These results suggest that the CMHs could provide an exceptional biomaterial for corneal stroma regeneration.
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Affiliation(s)
- Mark Ahearne
- 1 Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute , Trinity College Dublin, Dublin, Ireland .,2 Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin , Dublin, Ireland
| | - Amy P Lynch
- 1 Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute , Trinity College Dublin, Dublin, Ireland .,2 Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin , Dublin, Ireland
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Priyadarsini S, McKay TB, Sarker-Nag A, Karamichos D. Keratoconus in vitro and the key players of the TGF-β pathway. Mol Vis 2015; 21:577-88. [PMID: 26015770 PMCID: PMC4443584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 05/20/2015] [Indexed: 11/04/2022] Open
Abstract
PURPOSE Keratoconus (KC) is a corneal thinning disease of unknown etiology whose pathophysiology is correlated with the presence of a thin corneal stroma and altered extracellular matrix (ECM). Transforming growth factor-β (TGF-β) signaling is a key regulator of ECM secretion and assembly in multiple tissues, including the anterior segment of the eye, and it has been linked to KC. We have previously shown that human keratoconus cells (HKCs) have a myofibroblast phenotype and altered ECM assembly compared to normal human corneal fibroblasts (HCFs). Moreover, TGF-β3 treatment promotes assembly of a more normal stromal ECM and modulates the fibrotic phenotype in HKCs. Herein, we identify alterations in TGF-β signaling that contribute to the observed fibrotic phenotype in HKCs. METHODS HCFs and HKCs were stimulated with TGF-β1, TGF-β2, or TGF-β3 isoforms (0.1 ng/mL) in the presence of a stable vitamin C derivative (0.5 mM) for 4 weeks. All samples were examined using RT-PCR and western blotting to quantify changes in the expressions of key TGF-β signaling molecules between HCFs and HKCs. RESULTS We found a significant downregulation in the SMAD6 and SMAD7 expressions by HKCs when compared to HCFs (p≤0.05). Moreover, stimulation of HKCs with any of the three TGF-β isoforms did not significantly alter the expressions of SMAD6 or SMAD7. HCFs also showed an upregulation in TGF-βRI, TGF-βRII, and TGF-βRIII following TGF-β3 treatment, whereas HKCs showed a significant two-fold downregulation. CONCLUSIONS Overall, our data shows the decreased expressions of the regulatory SMADs SMAD6 and SMAD7 by HKCs contribute to the pathological ECM structure observed in KC, and TGF-β3 may attenuate this mechanism by downregulating the expression of the key profibrotic receptor, TGF-βRII. Our study suggests a significant role of altered regulation of TGF-β signaling in KC progression and that it may enable novel therapeutic developments targeting TGF-β receptor regulation.
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Affiliation(s)
- Shrestha Priyadarsini
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Tina B. McKay
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Akhee Sarker-Nag
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK
| | - Dimitrios Karamichos
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK,Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK
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40
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Koppaka V, Lakshman N, Petroll WM. Effect of HDAC Inhibitors on Corneal Keratocyte Mechanical Phenotypes in 3-D Collagen Matrices. Mol Vis 2015; 21:502-14. [PMID: 25999677 PMCID: PMC4415596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 04/27/2015] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Histone deacetylase inhibitors (HDAC) have been shown to inhibit the TGFβ-induced myofibroblast transformation of corneal fibroblasts in 2-D culture. However, the effect of HDAC inhibitors on keratocyte spreading, contraction, and matrix remodeling in 3-D culture has not been directly assessed. The goal of this study was to investigate the effects of the HDAC inhibitors Trichostatin A (TSA) and Vorinostat (SAHA) on corneal keratocyte mechanical phenotypes in 3-D culture using defined serum-free culture conditions. METHODS Rabbit corneal keratocytes were plated within standard rat tail type I collagen matrices (2.5 mg/ml) or compressed collagen matrices (~100 mg/ml) and cultured for up to 4 days in serum-free media, PDGF BB, TGFβ1, and either 50 nM TSA, 10 μM SAHA, or vehicle (DMSO). F-actin, α-SM-actin, and collagen fibrils were imaged using confocal microscopy. Cell morphology and global matrix contraction were quantified digitally. The expression of α-SM-actin was assessed using western blotting. RESULTS Corneal keratocytes in 3-D matrices had a quiescent mechanical phenotype, as indicated by a dendritic morphology, a lack of stress fibers, and minimal cell-induced matrix remodeling. This phenotype was generally maintained following the addition of TSA or SAHA. TGFβ1 induced a contractile phenotype, as indicated by a loss of dendritic cell processes, the development of stress fibers, and significant matrix compaction. In contrast, cells cultured in TGFβ1 plus TSA or SAHA remained dendritic and did not form stress fibers or induce ECM compaction. Western blotting showed that the expression of α-SM actin after treatment with TGFβ1 was inhibited by TSA and SAHA. PDGF BB stimulated the elongation of keratocytes and the extension of dendritic processes within 3-D matrices without inducing stress fiber formation or collagen reorganization. This spreading response was maintained in the presence of TSA or SAHA. CONCLUSIONS Overall, HDAC inhibitors appear to mitigate the effects of TGFβ1 on the transformation of corneal keratocytes to a contractile, myofibroblast phenotype in both compliant and rigid 3-D matrices while preserving normal cell spreading and their ability to respond to the pro-migratory growth factor PDGF.
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Affiliation(s)
- Vindhya Koppaka
- Department of Ophthalmology, University of Texas Southwestern Medical Center,
Dallas, TX
| | - Neema Lakshman
- Department of Ophthalmology, University of Texas Southwestern Medical Center,
Dallas, TX
| | - W Matthew Petroll
- Department of Ophthalmology, University of Texas Southwestern Medical Center,
Dallas, TX
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Petroll WM, Lakshman N. Fibroblastic Transformation of Corneal Keratocytes by Rac Inhibition is Modulated by Extracellular Matrix Structure and Stiffness. J Funct Biomater 2015; 6:222-40. [PMID: 25874856 PMCID: PMC4493509 DOI: 10.3390/jfb6020222] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 04/06/2015] [Accepted: 04/08/2015] [Indexed: 01/06/2023] Open
Abstract
The goal of this study was to investigate how alterations in extracellular matrix (ECM) biophysical properties modulate corneal keratocyte phenotypes in response to specific wound healing cytokines and Rho GTPases. Rabbit corneal keratocytes were plated within standard collagen matrices (2.5 mg/mL) or compressed collagen matrices (~100 mg/mL) and cultured in serum-free media, PDGF BB, IGF, FGF2 or TGFβ1, with or without the Rac1 inhibitor NSC23766 and/or the Rho kinase inhibitor Y-27632. After 1 to 4 days, cells were labeled for F-actin and imaged using confocal microscopy. Keratocytes within standard collagen matrices (which are highly compliant) maintained a dendritic phenotype following culture in serum-free media, PDGF, IGF and FGF, but developed stress fibers in TGFβ1. Keratocytes within compressed collagen (which has high stiffness and low porosity) maintained a dendritic phenotype following culture in serum-free media, PDGF and IGF, but developed stress fibers in both FGF and TGFβ1. The Rac inhibitor had no significant impact on growth factor responses in compliant matrices. Within compressed collagen matrices however, the Rac inhibitor induced fibroblastic transformation in serum-free media, PDGF and IGF. Fibroblast and myofibroblast transformation was blocked by Rho kinase inhibition. Overall, keratocyte growth factor responses appear to be regulated by both the interplay between Rho and Rac signaling, and the structural and mechanical properties of the ECM.
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Affiliation(s)
- W Matthew Petroll
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX 75390-9057, USA.
| | - Neema Lakshman
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, TX 75390-9057, USA.
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Petroll WM, Miron-Mendoza M. Mechanical interactions and crosstalk between corneal keratocytes and the extracellular matrix. Exp Eye Res 2015; 133:49-57. [PMID: 25819454 PMCID: PMC4379425 DOI: 10.1016/j.exer.2014.09.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 09/09/2014] [Accepted: 09/11/2014] [Indexed: 12/13/2022]
Abstract
The generation of cellular forces and the application of these physical forces to the ECM play a central role in mediating matrix patterning and remodeling during fundamental processes such as developmental morphogenesis and wound healing. In addition to growth factors and other biochemical factors that can modulate the keratocyte mechanical phenotype, another key player in the regulation of cell-induced ECM patterning is the mechanical state of the ECM itself. In this review we provide an overview of the biochemical and biophysical factors regulating the mechanical interactions between corneal keratocytes and the stromal ECM at the cellular level. We first provide an overview of how Rho GTPases regulate the sub-cellular pattern of force generation by corneal keratocytes, and the impact these forces have on the surrounding ECM. We next review how feedback from local matrix structural and mechanical properties can modulate keratocyte phenotype and mechanical activity. Throughout this review, we provide examples of how these biophysical interactions may contribute to clinical outcomes, with a focus on corneal wound healing.
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Affiliation(s)
- W Matthew Petroll
- Department of Ophthalmology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9057, USA.
| | - Miguel Miron-Mendoza
- Department of Ophthalmology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9057, USA
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43
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Kumar P, Satyam A, Fan X, Rochev Y, Rodriguez BJ, Gorelov A, Joshi L, Raghunath M, Pandit A, Zeugolis DI. Accelerated Development of Supramolecular Corneal Stromal-Like Assemblies from Corneal Fibroblasts in the Presence of Macromolecular Crowders. Tissue Eng Part C Methods 2015; 21:660-70. [PMID: 25535812 DOI: 10.1089/ten.tec.2014.0387] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Tissue engineering by self-assembly uses the cells' secretome as a regeneration template and biological factory of trophic factors. Despite the several advantages that have been witnessed in preclinical and clinical settings, the major obstacle for wide acceptance of this technology remains the tardy extracellular matrix formation. In this study, we assessed the influence of macromolecular crowding (MMC)/excluding volume effect, a biophysical phenomenon that accelerates thermodynamic activities and biological processes by several orders of magnitude, in human corneal fibroblast (HCF) culture. Our data indicate that the addition of negatively charged galactose derivative (carrageenan) in HCF culture, even at 0.5% serum, increases by 12-fold tissue-specific matrix deposition, while maintaining physiological cell morphology and protein/gene expression. Gene analysis indicates that a glucose derivative (dextran sulfate) may drive corneal fibroblasts toward a myofibroblast lineage. Collectively, these results indicate that MMC may be suitable not only for clinical translation and commercialization of tissue engineering by self-assembly therapies, but also for the development of in vitro pathophysiology models.
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Affiliation(s)
- Pramod Kumar
- 1 Network of Excellence for Functional Biomaterials (NFB), Bioscience Research Building, National University of Ireland Galway (NUI Galway) , Galway, Ireland
| | - Abhigyan Satyam
- 1 Network of Excellence for Functional Biomaterials (NFB), Bioscience Research Building, National University of Ireland Galway (NUI Galway) , Galway, Ireland
| | - Xingliang Fan
- 1 Network of Excellence for Functional Biomaterials (NFB), Bioscience Research Building, National University of Ireland Galway (NUI Galway) , Galway, Ireland
| | - Yury Rochev
- 1 Network of Excellence for Functional Biomaterials (NFB), Bioscience Research Building, National University of Ireland Galway (NUI Galway) , Galway, Ireland
| | - Brian J Rodriguez
- 2 Conway Institute of Biomolecular & Biomedical Research, University College Dublin , Dublin, Ireland
| | - Alexander Gorelov
- 3 School of Chemistry & Chemical Biology, University College Dublin , Dublin, Ireland
| | - Lokesh Joshi
- 4 Alimentary Glycoscience Research Cluster, NUI Galway , Galway, Ireland
| | - Michael Raghunath
- 5 Department of Bioengineering, Faculty of Engineering, National University of Singapore , Singapore, Singapore .,6 Tissue Engineering Programme, Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore , Singapore, Singapore
| | - Abhay Pandit
- 1 Network of Excellence for Functional Biomaterials (NFB), Bioscience Research Building, National University of Ireland Galway (NUI Galway) , Galway, Ireland
| | - Dimitrios I Zeugolis
- 1 Network of Excellence for Functional Biomaterials (NFB), Bioscience Research Building, National University of Ireland Galway (NUI Galway) , Galway, Ireland
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Macromolecularly crowded in vitro microenvironments accelerate the production of extracellular matrix-rich supramolecular assemblies. Sci Rep 2015; 5:8729. [PMID: 25736020 PMCID: PMC4348624 DOI: 10.1038/srep08729] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 01/27/2015] [Indexed: 12/13/2022] Open
Abstract
Therapeutic strategies based on the principles of tissue engineering by self-assembly put forward the notion that functional regeneration can be achieved by utilising the inherent capacity of cells to create highly sophisticated supramolecular assemblies. However, in dilute ex vivo microenvironments, prolonged culture time is required to develop an extracellular matrix-rich implantable device. Herein, we assessed the influence of macromolecular crowding, a biophysical phenomenon that regulates intra- and extra-cellular activities in multicellular organisms, in human corneal fibroblast culture. In the presence of macromolecules, abundant extracellular matrix deposition was evidenced as fast as 48 h in culture, even at low serum concentration. Temperature responsive copolymers allowed the detachment of dense and cohesive supramolecularly assembled living substitutes within 6 days in culture. Morphological, histological, gene and protein analysis assays demonstrated maintenance of tissue-specific function. Macromolecular crowding opens new avenues for a more rational design in engineering of clinically relevant tissue modules in vitro.
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45
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Miron-Mendoza M, Graham E, Kivanany P, Quiring J, Petroll WM. The Role of Thrombin and Cell Contractility in Regulating Clustering and Collective Migration of Corneal Fibroblasts in Different ECM Environments. Invest Ophthalmol Vis Sci 2015; 56:2079-90. [PMID: 25736789 PMCID: PMC4373543 DOI: 10.1167/iovs.15-16388] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 02/24/2015] [Indexed: 11/24/2022] Open
Abstract
PURPOSE We previously reported that extracellular matrix composition (fibrin versus collagen) modulates the pattern of corneal fibroblast spreading and migration in 3-D culture. In this study, we investigate the role of thrombin and cell contractility in mediating these differences in cell behavior. METHODS To assess cell spreading, corneal fibroblasts were plated on top of fibrillar collagen and fibrin matrices. To assess 3-dimensional cell migration, compacted collagen matrices seeded with corneal fibroblasts were embedded inside acellular collagen or fibrin matrices. Constructs were cultured in serum-free media containing platelet-derived growth factor (PDGF), with or without thrombin, the Rho kinase inhibitor Y-27632, and/or the myosin II inhibitor blebbistatin. We used 3-dimensional and 4-dimensional imaging to assess cell mechanical behavior, connectivity and cytoskeletal organization. RESULTS Thrombin stimulated increased contractility of corneal fibroblasts. Thrombin also induced Rho kinase-dependent clustering of cells plated on top of compliant collagen matrices, but not on rigid substrates. In contrast, cells on fibrin matrices coalesced into clusters even when Rho kinase was inhibited. In nested matrices, cells always migrated independently through collagen, even in the presence of thrombin. In contrast, cells migrating into fibrin formed an interconnected network. Both Y-27632 and blebbistatin reduced the migration rate in fibrin, but cells continued to migrate collectively. CONCLUSIONS The results suggest that while thrombin-induced actomyosin contraction can induce clustering of fibroblasts plated on top of compliant collagen matrices, it does not induce collective cell migration inside 3-D collagen constructs. Furthermore, increased contractility is not required for clustering or collective migration of corneal fibroblasts interacting with fibin.
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Affiliation(s)
- Miguel Miron-Mendoza
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Eric Graham
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Pouriska Kivanany
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Jonathan Quiring
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - W Matthew Petroll
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
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Kobayashi T, Shiraishi A, Hara Y, Kadota Y, Yang L, Inoue T, Shirakata Y, Ohashi Y. Stromal-epithelial interaction study: The effect of corneal epithelial cells on growth factor expression in stromal cells using organotypic culture model. Exp Eye Res 2015; 135:109-17. [PMID: 25682729 DOI: 10.1016/j.exer.2015.02.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 02/09/2015] [Accepted: 02/11/2015] [Indexed: 11/29/2022]
Abstract
Interactions between stromal and epithelial cells play important roles in the development, homeostasis, and pathological conditions of the cornea. Soluble cytokines are critical factors in stromal-epithelial interactions, and growth factors secreted from corneal stromal cells contribute to the regulation of proliferation and differentiation of corneal epithelial cells (CECs). However, the manner in which the expression of growth factors is regulated in stromal cells has not been completely determined. To study stromal-epithelial cell interactions, we used an organotypic culture model. Human or rabbit CECs (HCECs or RCECs) were cultured on amniotic membranes placed on human corneal fibroblasts (HCFs) embedded in a collagen gel. The properties of the organotypic culture were examined by hematoxylin-eosin staining and immunofluorescence. In the organotypic culture, HCECs or RCECs were stratified into two-three layers after five days and five-seven layers after nine days. However, stratification was not observed when the HCECs were seeded on a collagen gel without fibroblasts. K3/K12 were expressed on day 9. The HCF-embedded collagen gels were collected on days 3, 5, or 9 after seeding the RCECs, and mRNA expression of growth factors FGF7, HGF, NGF, EGF, TGF-α, SCF, TGF-β1, TGF-β2, and TGF-β3 were quantified by real-time PCR. mRNA expression of the growth factors in HCFs cultured with RCECs were compared with those cultured without RCECs, as well as in monolayer cultures. mRNA expression of TGF-α was markedly increased in HCFs cultured with RCECs. However, mRNA expression of the TGF-β family was suppressed in HCFs cultured with RCECs. Principal component analysis revealed that mRNA expression of the growth factors in HCFs were generally similar when they were cultured with RCECs. In organotypic cultures, the morphological changes in the CECs and the expression patterns of the growth factors in the stromal cells clearly demonstrated stromal-epithelial cell interactions, and the results suggest that stromal cells and epithelial cells may act in concert in the cornea.
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Affiliation(s)
- Takeshi Kobayashi
- Department of Ophthalmology and Regenerative Medicine, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan; Department of Stem Cell Biology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Atsushi Shiraishi
- Department of Ophthalmology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan; Department of Stem Cell Biology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan.
| | - Yuko Hara
- Department of Ophthalmology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Yuko Kadota
- Department of Ophthalmology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Lujun Yang
- Department of Dermatology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Tomoyuki Inoue
- Department of Ophthalmology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Yuji Shirakata
- Department of Dermatology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
| | - Yuichi Ohashi
- Department of Ophthalmology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan; Department of Infectious Diseases, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime 791-0295, Japan
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Marelli B, Ghezzi CE, James-Bhasin M, Nazhat SN. Fabrication of injectable, cellular, anisotropic collagen tissue equivalents with modular fibrillar densities. Biomaterials 2015; 37:183-93. [DOI: 10.1016/j.biomaterials.2014.10.019] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 10/02/2014] [Indexed: 12/13/2022]
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Gross cystic disease fluid protein-15/prolactin-inducible protein as a biomarker for keratoconus disease. PLoS One 2014; 9:e113310. [PMID: 25405607 PMCID: PMC4236164 DOI: 10.1371/journal.pone.0113310] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 10/21/2014] [Indexed: 12/14/2022] Open
Abstract
Keratoconus (KC) is a bilateral degenerative disease of the cornea characterized by corneal bulging, stromal thinning, and scarring. The etiology of the disease is unknown. In this study, we identified a new biomarker for KC that is present in vivo and in vitro. In vivo, tear samples were collected from age-matched controls with no eye disease (n = 36) and KC diagnosed subjects (n = 17). Samples were processed for proteomics using LC-MS/MS. In vitro, cells were isolated from controls (Human Corneal Fibroblasts-HCF) and KC subjects (Human Keratoconus Cells-HKC) and stimulated with a Vitamin C (VitC) derivative for 4 weeks, and with one of the three transforming growth factor-beta (TGF-β) isoforms. Samples were analyzed using real-time PCR and Western Blots. By using proteomics analysis, the Gross cystic disease fluid protein-15 (GCDFP-15) or prolactin-inducible protein (PIP) was found to be the best independent biomarker able to discriminate between KC and controls. The intensity of GCDFP-15/PIP was significantly higher in healthy subjects compared to KC-diagnosed. Similar findings were seen in vitro, using a 3D culture model. All three TGF-β isoforms significantly down-regulated the expression of GCDFP-15/PIP. Zinc-alpha-2-glycoprotein (AZGP1), a protein that binds to PIP, was identified by proteomics and cell culture to be highly regulated. In this study by different complementary techniques we confirmed the potential role of GCDFP-15/PIP as a novel biomarker for KC disease. It is likely that exploring the GCDFP-15/PIP-AZGP1 interactions will help better understand the mechanism of KC disease.
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Yam GHF, Yusoff NZBM, Kadaba A, Tian D, Myint HH, Beuerman RW, Zhou L, Mehta JS. Ex Vivo Propagation of Human Corneal Stromal "Activated Keratocytes" for Tissue Engineering. Cell Transplant 2014; 24:1845-61. [PMID: 25291523 DOI: 10.3727/096368914x685069] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Keratoconus is a corneal disorder characterized by a thinning of stromal tissue, and the affected patients have induced astigmatism and visual impairment. It is associated with a loss of corneal stromal keratocytes (CSKs). Hence, reconstructing stromal tissue with autologous CSK replacement can be a viable alternative to corneal transplantation, which is restricted by the global donor material shortage and graft rejection. Human CSKs are normally quiescent and express unique markers, like aldehyde dehydrogenases and keratocan. In serum culture, they proliferate, but lose their characteristic phenotype and become stromal fibroblasts. Here we report a novel culture cocktail to ex vivo propagate and maintain CSKs. Primary human CSKs were obtained from adult donors and cultured with soluble human amnion stromal extract (ASE), rho-associated coiled-coil-forming protein serine/threonine kinase inhibitor Y-27632, and insulin-like growth factor-1 (collectively named as ERI). Protein profiling using mass spectrometry followed by MetaCore™ pathway analysis predicted that ASE proteins might participate in transforming growth factor-β (TGF-β) signaling and fibroblast development, cell adhesion, extracellular matrix remodeling, and immune response. In culture with 0.5% fetal bovine serum and ERI, the population of "activated keratocytes" was expanded. They had much lowered expression of both keratocyte and fibroblast markers, suppressed TGF-β-mediated Smad2/3 activation, and lacked fibroblast-mediated collagen contractibility. These "activated keratoctyes" could be propagated for six to eight passages ex vivo, and they regained CSK-specific dendritic morphology and gene marker expression, including aldehyde dehydrogenases, lumican, and keratocan biosynthesis, expression, and secretion when returned to serum-depleted ERI condition. This novel cocktail maintained human CSKs in both adherent and suspension cultures with proper keratocyte features and without the transformation to stromal fibroblasts. Thus, human CSKs can be ex vivo propagated as transient "activated keratocytes." This could provide sufficient number of genuine CSKs for corneal tissue engineering.
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Affiliation(s)
- Gary Hin-Fai Yam
- Tissue Engineering and Stem Cell Group, Singapore Eye Research Institute, Singapore
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Feng Z, Wagatsuma Y, Kikuchi M, Kosawada T, Nakamura T, Sato D, Shirasawa N, Kitajima T, Umezu M. The mechanisms of fibroblast-mediated compaction of collagen gels and the mechanical niche around individual fibroblasts. Biomaterials 2014; 35:8078-91. [DOI: 10.1016/j.biomaterials.2014.05.072] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 05/24/2014] [Indexed: 12/22/2022]
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