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Van L, Bennett S, Nicholas SE, Hjortdal J, McKay TB, Karamichos D. Prospective Observational Study Evaluating Systemic Hormones and Corneal Crosslinking Effects in Keratoconus. Ophthalmol Sci 2024; 4:100364. [PMID: 37868794 PMCID: PMC10585634 DOI: 10.1016/j.xops.2023.100364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 10/24/2023]
Abstract
Purpose To evaluate associations between hormone levels and corneal parameters in patients with keratoconus (KC), before and after photooxidative corneal collagen crosslinking (CXL). Design Prospective, observational cohort study. Participants Twenty-eight patients with KC who were scheduled for CXL at Aarhus University Hospital in Denmark. Methods Androgen (dehydroepiandrosterone sulfate [DHEA-S]) and estrogen (estrone and estriol) plasma levels were measured and clinical assessments were performed before CXL and 2 to 3 months post-CXL, comparing the CXL eye with the control eye from the same participant. Main Outcome Measures Associations between hormone levels and maximum corneal curvature (Kmax) and minimum central corneal thickness (CCtmin) before and after CXL. Results Corneal collagen crosslinking was associated with a 2% reduction in Kmax values in the CXL eye, post-CXL, from baseline (median, 56.8 diopters [D]; 95% confidence interval [CI], 50.4-60.3) to the second visit (55.7 D; 95% CI, 50.4-58.8; P < 0.001). Systemic DHEA-S levels were 5 to 6 orders of magnitude higher than estriol or estrone concentrations in plasma. Importantly, estriol levels, rather than DHEA-S or estrone levels, were more closely correlated with Kmax before CXL (Spearman's r = 0.55, P = 0.01). Post-CXL Kmax and CCtmin were not associated with DHEA-S, estrone, or estriol plasma levels at the same timepoint. Conclusions This study provides supporting evidence based on a KC clinical population that systemic estrogen levels may influence corneal parameters (curvature and thickness) pre-CXL. Further studies evaluating the interplay between the therapeutic benefits of CXL and systemic hormone distributions are needed to determine if perturbation of the local corneal microenvironment influences endocrine function. Financial Disclosures The authors have no proprietary or commercial interest in any materials discussed in this article.
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Affiliation(s)
- Lyly Van
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Sashia Bennett
- Department of Ophthalmology, Aarhus University Hospital, 8200 Aarhus N, Denmark
| | - Sarah E. Nicholas
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas
- Department of Pharmaceutical Sciences, University of North Texas Health Science Center, Fort Worth, Texas
| | - Jesper Hjortdal
- Department of Ophthalmology, Aarhus University Hospital, 8200 Aarhus N, Denmark
| | - Tina B. McKay
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Dimitrios Karamichos
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas
- Department of Pharmaceutical Sciences, University of North Texas Health Science Center, Fort Worth, Texas
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas
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Priyadarsini S, McKay TB, Escandon P, Nicholas SE, Ma JX, Karamichos D. Cell sheet-based approach to study the diabetic corneal stroma. Exp Eye Res 2023; 237:109717. [PMID: 37944849 DOI: 10.1016/j.exer.2023.109717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/24/2023] [Accepted: 11/06/2023] [Indexed: 11/12/2023]
Abstract
Prolonged hyperglycemia during diabetes mellitus (DM) is associated with severe complications that may affect both the anterior and posterior ocular segments, leading to impaired vision or blindness. The cornea is a vital part of the eye that has a dual role as a protective transparent barrier and as a major refractive structure and is likewise negatively affected by hyperglycemia in DM. Understanding the cellular and molecular mechanisms underlying the phenotypic changes associated with DM is critical to developing targeted therapies to promote tissue integrity. In this proof-of-concept study, we applied a cell sheet-based approach to generate stacked constructs of physiological corneal thickness using primary human corneal fibroblasts isolated from cadaveric control (healthy), Type 1 DM and Type 2 DM corneal tissues. Self-assembled corneal stromal sheets were generated after 2 weeks in culture, isolated, and subsequently assembled to create stacked constructs, which were evaluated using transmission electron microscopy. Analysis of gene expression patterns revealed significant downregulation of fibrotic markers, α-smooth muscle actin, and collagen type 3, with stacking in Type 2 DM constructs when compared to controls. IGF1 expression was significantly upregulated in Type 2 DM constructs compared to controls with a significant reduction induced by stacking. This study describes the development of a thicker, self-assembled corneal stromal construct as a platform to evaluate phenotypic differences associated with DM-derived corneal fibroblasts and enable the development of targeted therapeutics to promote corneal integrity.
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Affiliation(s)
- Shrestha Priyadarsini
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Tina B McKay
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Paulina Escandon
- 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
| | - 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
| | - Jian-Xing Ma
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC, 27101, 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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McKay TB, Khawaja ZQ, Freedman IG, Turco I, Wiredu K, Colecchi T, Akeju O. Exploring the Pathophysiology of Delirium: An Overview of Biomarker Studies, Animal Models, and Tissue-Engineered Models. Anesth Analg 2023; 137:1186-1197. [PMID: 37851904 PMCID: PMC10840625 DOI: 10.1213/ane.0000000000006715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
Delirium is an acute brain disorder associated with disorganized thinking, difficulty focusing, and confusion that commonly follows major surgery, severe infection, and illness. Older patients are at high risk for developing delirium during hospitalization, which may contribute to increased morbidity, longer hospitalization, and increased risk of institutionalization following discharge. The pathophysiology underlying delirium remains poorly studied. This review delves into the findings from biomarker studies and animal models, and highlights the potential for tissue-engineered models of the brain in studying this condition. The aim is to bring together the existing knowledge in the field and provide insight into the future direction of delirium research.
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Affiliation(s)
- Tina B. McKay
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Zain Q. Khawaja
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Isaac G. Freedman
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Isabella Turco
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Kwame Wiredu
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Talia Colecchi
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Oluwaseun Akeju
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA
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Wiredu K, Mueller A, McKay TB, Behera A, Shaefi S, Akeju O. Sex Differences in the Incidence of Postoperative Delirium after Cardiac Surgery: A Pooled Analyses of Clinical Trials. Anesthesiology 2023; 139:540-542. [PMID: 37535937 PMCID: PMC10529077 DOI: 10.1097/aln.0000000000004656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Affiliation(s)
- Kwame Wiredu
- Massachusetts General Hospital, Boston, Massachusetts (K.W.).
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McKay TB, Emmitte KA, German C, Karamichos D. Quercetin and Related Analogs as Therapeutics to Promote Tissue Repair. Bioengineering (Basel) 2023; 10:1127. [PMID: 37892857 PMCID: PMC10604618 DOI: 10.3390/bioengineering10101127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/11/2023] [Accepted: 09/21/2023] [Indexed: 10/29/2023] Open
Abstract
Quercetin is a polyphenol of the flavonoid class of secondary metabolites that is widely distributed in the plant kingdom. Quercetin has been found to exhibit potent bioactivity in the areas of wound healing, neuroprotection, and anti-aging research. Naturally found in highly glycosylated forms, aglycone quercetin has low solubility in aqueous environments, which has heavily limited its clinical applications. To improve the stability and bioavailability of quercetin, efforts have been made to chemically modify quercetin and related flavonoids so as to improve aqueous solubility while retaining bioactivity. In this review, we provide an updated overview of the biological properties of quercetin and proposed mechanisms of actions in the context of wound healing and aging. We also provide a description of recent developments in synthetic approaches to improve the solubility and stability of quercetin and related analogs for therapeutic applications. Further research in these areas is expected to enable translational applications to improve ocular wound healing and tissue repair.
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Affiliation(s)
- Tina B. McKay
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA;
| | - Kyle A. Emmitte
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA;
| | - Carrie German
- CFD Research Corporation, Computational Biology Division, Huntsville, AL 35806, USA;
| | - Dimitrios Karamichos
- Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA;
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
- Department of Pharmacology and Neuroscience, School of Biomedical Sciences, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
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Qu JZ, Mueller A, McKay TB, Westover MB, Shelton KT, Shaefi S, D'Alessandro DA, Berra L, Brown EN, Houle TT, Akeju O. Nighttime dexmedetomidine for delirium prevention in non-mechanically ventilated patients after cardiac surgery (MINDDS): A single-centre, parallel-arm, randomised, placebo-controlled superiority trial. EClinicalMedicine 2023; 56:101796. [PMID: 36590787 PMCID: PMC9800196 DOI: 10.1016/j.eclinm.2022.101796] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND The delirium-sparing effect of nighttime dexmedetomidine has not been studied after surgery. We hypothesised that a nighttime dose of dexmedetomidine would reduce the incidence of postoperative delirium as compared to placebo. METHODS This single-centre, parallel-arm, randomised, placebo-controlled superiority trial evaluated whether a short nighttime dose of intravenous dexmedetomidine (1 μg/kg over 40 min) would reduce the incidence of postoperative delirium in patients 60 years of age or older undergoing elective cardiac surgery with cardiopulmonary bypass. Patients were randomised to receive dexmedetomidine or placebo in a 1:1 ratio. The primary outcome was delirium on postoperative day one. Secondary outcomes included delirium within three days of surgery, 30-, 90-, and 180-day abbreviated Montreal Cognitive Assessment scores, Patient Reported Outcome Measures Information System quality of life scores, and all-cause mortality. The study was registered as NCT02856594 on ClinicalTrials.gov on August 5, 2016, before the enrolment of any participants. FINDINGS Of 469 patients that underwent randomisation to placebo (n = 235) or dexmedetomidine (n = 234), 75 met a prespecified drop criterion before the study intervention. Thus, 394 participants (188 dexmedetomidine; 206 placebo) were analysed in the modified intention-to-treat cohort (median age 69 [IQR 64, 74] years; 73.1% male [n = 288]; 26·9% female [n = 106]). Postoperative delirium status on day one was missing for 30 (7.6%) patients. Among those in whom it could be assessed, the primary outcome occurred in 5 of 175 patients (2.9%) in the dexmedetomidine group and 16 of 189 patients (8.5%) in the placebo group (OR 0.32, 95% CI: 0.10-0.83; P = 0.029). A non-significant but higher proportion of participants experienced delirium within three days postoperatively in the placebo group (25/177; 14.1%) compared to the dexmedetomidine group (14/160; 8.8%; OR 0.58; 95% CI, 0.28-1.15). No significant differences between groups were observed in secondary outcomes or safety. INTERPRETATION Our findings suggested that in elderly cardiac surgery patients with a low baseline risk of postoperative delirium and extubated within 12 h of ICU admission, a short nighttime dose of dexmedetomidine decreased the incidence of delirium on postoperative day one. Although non-statistically significant, our findings also suggested a clinical meaningful difference in the three-day incidence of postoperative delirium. FUNDING National Institute on Aging (R01AG053582).
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Affiliation(s)
- Jason Z. Qu
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Ariel Mueller
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tina B. McKay
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - M. Brandon Westover
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Kenneth T. Shelton
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Shahzad Shaefi
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - David A. D'Alessandro
- Division of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Lorenzo Berra
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Respiratory Care Services, Massachusetts General Hospital, Boston, MA, USA
| | - Emery N. Brown
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Timothy T. Houle
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Oluwaseun Akeju
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Corresponding author. Massachusetts General Hospital, 55 Fruit Street, Gray Bigelow 444, Boston, MA 02114, USA.
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Shu DY, Chaudhary S, Cho KS, Lennikov A, Miller WP, Thorn DC, Yang M, McKay TB. Role of Oxidative Stress in Ocular Diseases: A Balancing Act. Metabolites 2023; 13:187. [PMID: 36837806 PMCID: PMC9960073 DOI: 10.3390/metabo13020187] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/22/2023] [Accepted: 01/24/2023] [Indexed: 01/31/2023] Open
Abstract
Redox homeostasis is a delicate balancing act of maintaining appropriate levels of antioxidant defense mechanisms and reactive oxidizing oxygen and nitrogen species. Any disruption of this balance leads to oxidative stress, which is a key pathogenic factor in several ocular diseases. In this review, we present the current evidence for oxidative stress and mitochondrial dysfunction in conditions affecting both the anterior segment (e.g., dry eye disease, keratoconus, cataract) and posterior segment (age-related macular degeneration, proliferative vitreoretinopathy, diabetic retinopathy, glaucoma) of the human eye. We posit that further development of therapeutic interventions to promote pro-regenerative responses and maintenance of the redox balance may delay or prevent the progression of these major ocular pathologies. Continued efforts in this field will not only yield a better understanding of the molecular mechanisms underlying the pathogenesis of ocular diseases but also enable the identification of novel druggable redox targets and antioxidant therapies.
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Affiliation(s)
- Daisy Y. Shu
- Department of Ophthalmology, Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
| | - Suman Chaudhary
- Department of Ophthalmology, Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
| | - Kin-Sang Cho
- Department of Ophthalmology, Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
| | - Anton Lennikov
- Department of Ophthalmology, Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
| | - William P. Miller
- Department of Ophthalmology, Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
| | - David C. Thorn
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| | - Menglu Yang
- Department of Ophthalmology, Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, Boston, MA 02114, USA
| | - Tina B. McKay
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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McKay TB, Qu J, Liang F, Mueller A, Wiener-Kronish J, Xie Z, Akeju O. Tau as a serum biomarker of delirium after major cardiac surgery: a single centre case-control study. Br J Anaesth 2022; 129:e13-e16. [DOI: 10.1016/j.bja.2022.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 03/28/2022] [Accepted: 04/03/2022] [Indexed: 11/29/2022] Open
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Abstract
The growth and maintenance of nearly every tissue in the body is influenced by systemic hormones during embryonic development through puberty and into adulthood. Of the ~130 different hormones expressed in the human body, steroid hormones and peptide hormones are highly abundant in circulation and are known to regulate anabolic processes and wound healing in a tissue-dependent manner. Of interest, differential levels of sex hormones have been associated with ocular pathologies, including dry eye disease and keratoconus. In this review, we discuss key studies that have revealed a role for androgens and estrogens in the cornea with focus on ocular surface homeostasis, wound healing, and stromal thickness. We also review studies of human growth hormone and insulin growth factor-1 in influencing ocular growth and epithelial regeneration. While it is unclear if endogenous hormones contribute to differential corneal wound healing in common animal models, the abundance of evidence suggests that systemic hormone levels, as a function of age, should be considered as an experimental variable in studies of corneal health and disease.
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Affiliation(s)
- Tina B. McKay
- Department of Cell Biology, University of Oklahoma Health Sciences, Oklahoma City, OK 73104, 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
- Correspondence: ; Tel.: +1-817-735-2101
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McKay TB, Rhee J, Colon K, Adelsberger K, Turco I, Mueller A, Qu J, Akeju O. Preliminary Study of Serum Biomarkers Associated With Delirium After Major Cardiac Surgery. J Cardiothorac Vasc Anesth 2022; 36:118-124. [PMID: 34112563 PMCID: PMC8586054 DOI: 10.1053/j.jvca.2021.05.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/30/2021] [Accepted: 05/03/2021] [Indexed: 01/03/2023]
Abstract
OBJECTIVES The objective of this study was to identify novel serum biomarkers specific to postoperative delirium after major cardiac surgery to provide insight into the pathologic processes involved in delirium and its sequelae. DESIGN Nested, case-control study. SETTING Cardiac surgical intensive care unit in a single-site hospital setting. PARTICIPANTS The study comprised 24 older adults (aged >60 years) undergoing major cardiac surgery with cardiopulmonary bypass. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS The primary outcome was a positive screen for delirium from postoperative days one through three based on criteria included in the long form of the Confusion Assessment Method. A multiplexed proteomic approach was applied using proximity extension assays to identify and quantify proteins found in serum collected on the day of surgery and postoperative day one in delirious and nondelirious patient cohorts. An increase in serum fibroblast growth factor (FGF)-21 levels was identified in the delirious cohort from a presurgery baseline of (mean ± standard deviation) 5.0 ± 1.1 log2 abundance (95% confidence interval [CI], 4.3-5.7) to 6.7 ± 1.6 log2 abundance (95% CI, 5.7-7.7; p = 0.01) postsurgery. A similar increase was identified in FGF-23 from a presurgery baseline of 1.7 ± 1.3 log2 abundance (95% CI, 0.8-2.5) to 3.4 ± 2.2 log2 abundance (95% CI, 2.0-4.8; p = 0.06) postsurgery. An increase in interleukin-6 serum levels also was identified in the delirious cohort from a presurgery baseline of 3.8 ± 1.1 log2 abundance (95% CI, 3.1-4.5) to 8.7 ± 1.9 log2 abundance (95% CI, 7.5-9.9; p < 0.0001) postsurgery. However, the increase in interleukin-6 serum levels of the nondelirious cohort also met the study's threshold for statistical significance (p < 0.0001). Finally, an increase in monocyte chemotactic protein-3 serum levels was identified in the delirious cohort from a presurgery baseline of 4.1 ± 0.9 log2 abundance (95% CI, 3.6-4.7) to 6.1 ± 2.0 log2 abundance (95% CI, 4.8-7; p = 0.009) postsurgery. CONCLUSIONS FGF-21, FGF-23, interleukin-6, and monocyte chemotactic protein-3 serum levels were increased postoperatively in patients who developed delirium after major cardiac surgery. This study identified two members of the FGF family as potential putative systemic biomarkers for postoperative delirium after cardiac surgery, suggesting a possible role for metabolic recovery in the pathophysiologic mechanisms underlying neurocognitive dysfunction.
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Affiliation(s)
- Tina B. McKay
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit St, Boston, MA,Corresponding author at: 55 Fruit St, Boston, MA and/or
| | - James Rhee
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit St, Boston, MA,Corrigan Minehan Heart Center, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA
| | - Katia Colon
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit St, Boston, MA
| | - Katherine Adelsberger
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit St, Boston, MA
| | - Isabella Turco
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit St, Boston, MA
| | - Ariel Mueller
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit St, Boston, MA
| | - Jason Qu
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit St, Boston, MA
| | - Oluwaseun Akeju
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, 55 Fruit St, Boston, MA,Corresponding author at: 55 Fruit St, Boston, MA and/or
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McKay TB, Priyadarsini S, Rowsey T, Karamichos D. Arginine Supplementation Promotes Extracellular Matrix and Metabolic Changes in Keratoconus. Cells 2021; 10:cells10082076. [PMID: 34440845 PMCID: PMC8394349 DOI: 10.3390/cells10082076] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/03/2021] [Accepted: 08/10/2021] [Indexed: 11/16/2022] Open
Abstract
Keratoconus (KC) is a common corneal ectatic disease that affects 1:500–1:2000 people worldwide and is associated with a progressive thinning of the corneal stroma that may lead to severe astigmatism and visual deficits. Riboflavin-mediated collagen crosslinking currently remains the only approved treatment to halt progressive corneal thinning associated with KC by improving the biomechanical properties of the stroma. Treatments designed to increase collagen deposition by resident corneal stromal keratocytes remain elusive. In this study, we evaluated the effects of arginine supplementation on steady-state levels of arginine and arginine-related metabolites (e.g., ornithine, proline, hydroxyproline, spermidine, and putrescine) and collagen protein expression by primary human corneal fibroblasts isolated from KC and non-KC (healthy) corneas and cultured in an established 3D in vitro model. We identified lower cytoplasmic arginine and spermidine levels in KC-derived constructs compared to healthy controls, which corresponded with overall higher gene expression of arginase. Arginine supplementation led to a robust increase in cytoplasmic arginine, ornithine, and spermidine levels in controls only and a significant increase in collagen type I secretion in KC-derived constructs. Further studies evaluating safety and efficacy of arginine supplementation are required to elucidate the potential therapeutic applications of modulating collagen deposition in the context of KC.
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Affiliation(s)
- Tina B McKay
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | | | - Tyler Rowsey
- Dean McGee Eye Institute, Oklahoma City, OK 73104, 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
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McKay TB, Guo X, Hutcheon AEK, Karamichos D, Ciolino JB. Methods for Investigating Corneal Cell Interactions and Extracellular Vesicles In Vitro. ACTA ACUST UNITED AC 2021; 89:e114. [PMID: 32986311 DOI: 10.1002/cpcb.114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Science and medicine have become increasingly "human-centric" over the years. A growing shift away from the use of animals in basic research has led to the development of sophisticated in vitro models of various tissues utilizing human-derived cells to study physiology and disease. The human cornea has likewise been modeled in vitro using primary cells derived from corneas obtained from cadavers or post-transplantation. By utilizing a cell's intrinsic ability to maintain its tissue phenotype in a pre-designed microenvironment containing the required growth factors, physiological temperature, and humidity, tissue-engineered corneas can be grown and maintained in culture for relatively long periods of time on the scale of weeks to months. Due to its transparency and avascularity, the cornea is an optimal tissue for studies of extracellular matrix and cell-cell interactions, toxicology and permeability of drugs, and underlying mechanisms of scarring and tissue regeneration. This paper describes methods for the cultivation of corneal keratocytes, fibroblasts, epithelial, and endothelial cells for in vitro applications. We also provide detailed, step-by-step protocols for assembling and culturing 3D constructs of the corneal stroma, epithelial- and endothelial-stromal co-cultures and isolation of extracellular vesicles. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Isolating and culturing human corneal keratocytes and fibroblasts Basic Protocol 2: Isolating and culturing human corneal epithelial cells Basic Protocol 3: Isolating and culturing human corneal endothelial cells Basic Protocol 4: 3D corneal stromal construct assembly Basic Protocol 5: 3D corneal epithelial-stromal construct assembly Basic Protocol 6: 3D corneal endothelial-stromal construct assembly Basic Protocol 7: Isolating extracellular vesicles from corneal cell conditioned medium Support Protocol: Cryopreserving human corneal fibroblasts, corneal epithelial cells, and corneal endothelial cells.
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Affiliation(s)
- Tina B McKay
- Schepens Eye Research Institute of Massachusetts Eye and Ear and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
| | - Xiaoqing Guo
- Schepens Eye Research Institute of Massachusetts Eye and Ear and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
| | - Audrey E K Hutcheon
- Schepens Eye Research Institute of Massachusetts Eye and Ear and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
| | - Dimitrios Karamichos
- Department of Pharmaceutical Sciences and The North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas
| | - Joseph B Ciolino
- Schepens Eye Research Institute of Massachusetts Eye and Ear and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
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13
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McKay TB, Yeung V, Hutcheon AEK, Guo X, Zieske JD, Ciolino JB. Extracellular Vesicles in the Cornea: Insights from Other Tissues. Anal Cell Pathol (Amst) 2021; 2021:9983900. [PMID: 34336556 PMCID: PMC8324376 DOI: 10.1155/2021/9983900] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 07/10/2021] [Indexed: 02/07/2023] Open
Abstract
Extracellular vesicles (EVs) are phospholipid bilayer-bound particles secreted by cells that have been found to be important in mediating cell-cell communication, signal transduction, and extracellular matrix remodeling. Their role in both physiological and pathological processes has been established in different tissues throughout the human body. The human cornea functions as a transparent and refractive barrier that protects the intraocular elements from the external environment. Injury, infection, or disease may cause the loss of corneal clarity by altering extracellular matrix organization within the stroma that may lead to detrimental effects on visual acuity. Over the years, numerous studies have identified many of the growth factors (e.g., transforming growth factor-β1, thrombospondin-1, and platelet-derived growth factor) important in corneal wound healing and scarring. However, the functional role of bound factors encapsulated in EVs in the context of corneal biology is less defined. In this review, we describe the discovery and characterization of EVs in the cornea. We focus on EV-matrix interactions, potential functions during corneal wound healing, and the bioactivity of mesenchymal stem cell-derived EVs. We also discuss the development of EVs as stable, drug-loaded therapeutics for ocular applications.
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Affiliation(s)
- Tina B. McKay
- Department of Ophthalmology, Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, 20 Staniford Street, Boston, MA 02114, USA
| | - Vincent Yeung
- Department of Ophthalmology, Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, 20 Staniford Street, Boston, MA 02114, USA
| | - Audrey E. K. Hutcheon
- Department of Ophthalmology, Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, 20 Staniford Street, Boston, MA 02114, USA
| | - Xiaoqing Guo
- Department of Ophthalmology, Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, 20 Staniford Street, Boston, MA 02114, USA
| | - James D. Zieske
- Department of Ophthalmology, Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, 20 Staniford Street, Boston, MA 02114, USA
| | - Joseph B. Ciolino
- Department of Ophthalmology, Schepens Eye Research Institute of Mass Eye and Ear, Harvard Medical School, 20 Staniford Street, Boston, MA 02114, USA
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Pollard RE, McKay TB, Ford A, Cairns DM, Georgakoudi I, Kaplan DL. Induction of Irritation and Inflammation in a 3D Innervated Tissue Model of the Human Cornea. ACS Biomater Sci Eng 2020; 6:6886-6895. [PMID: 33320598 DOI: 10.1021/acsbiomaterials.0c01136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Detection of slight changes in the chemical, thermal, and physical environments of the ocular surface is necessary to protect eyesight. The cornea, as the most densely innervated peripheral tissue in the body, can be damaged as a result of caustic chemical exposure. Such damage can be painful and debilitating, thus underscoring the need to understand mechanisms of ocular irritation. Both ethical and translational limitations regarding the use of animal subjects in part drive the need to develop relevant in vitro cell and tissue models that emulate the physiology of the human cornea. In this study, we utilized our 3D in vitro cornea-like tissue model to study the effects of irritation mediated by transient receptor potential (TRP) channels vanilloid 1 and ankyrin 1 (TRPV1; TRPA1) in response to allyl isothiocyanate (AITC) stimulation. Changes in gene expression were analyzed to characterize wound healing responses of the epithelial, stromal, and neuronal cell populations in the corneal tissue models. Key findings of the study include indications of wound healing, such as stromal myofibroblast differentiation and epithelial barrier re-establishment, amplification of pro-inflammatory cytokines, and downstream ECM protein remodeling due to irritation with the addition of sensory innervation. This study further establishes this in vitro tissue model as a useful tool for studying corneal irritation in vitro in a holistic manner with promise as a novel and sensitive tool for studying chemical exposures and subsequent responses.
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Affiliation(s)
- Rachel E Pollard
- Department of Biomedical Engineering, Tufts University, 4 Colby St, Medford, Massachusetts 02155, United States
| | - Tina B McKay
- Department of Biomedical Engineering, Tufts University, 4 Colby St, Medford, Massachusetts 02155, United States
| | - Andrew Ford
- Department of Biomedical Engineering, Tufts University, 4 Colby St, Medford, Massachusetts 02155, United States
| | - Dana M Cairns
- Department of Biomedical Engineering, Tufts University, 4 Colby St, Medford, Massachusetts 02155, United States
| | - Irene Georgakoudi
- Department of Biomedical Engineering, Tufts University, 4 Colby St, Medford, Massachusetts 02155, United States
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, 4 Colby St, Medford, Massachusetts 02155, United States
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McKay TB, Hutcheon AEK, Guo X, Zieske JD, Karamichos D. Modeling the cornea in 3-dimensions: Current and future perspectives. Exp Eye Res 2020; 197:108127. [PMID: 32619578 PMCID: PMC8116933 DOI: 10.1016/j.exer.2020.108127] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 06/17/2020] [Accepted: 06/23/2020] [Indexed: 02/08/2023]
Abstract
The cornea is an avascular, transparent ocular tissue that serves as a refractive and protective structure for the eye. Over 90% of the cornea is composed of a collagenous-rich extracellular matrix within the stroma with the other 10% composed by the corneal epithelium and endothelium layers and their corresponding supporting collagen layers (e.g., Bowman's and Descemet's membranes) at the anterior and posterior cornea, respectively. Due to its prominent role in corneal structure, tissue engineering approaches to model the human cornea in vitro have focused heavily on the cellular and functional properties of the corneal stroma. In this review, we discuss model development in the context of culture dimensionality (e.g., 2-dimensional versus 3-dimensional) and expand on the optical, biomechanical, and cellular functions promoted by the culture microenvironment. We describe current methods to model the human cornea with focus on organotypic approaches, compressed collagen, bioprinting, and self-assembled stromal models. We also expand on co-culture applications with the inclusion of relevant corneal cell types, such as epithelial, stromal keratocyte or fibroblast, endothelial, and neuronal cells. Further advancements in corneal tissue model development will markedly improve our current understanding of corneal wound healing and regeneration.
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Affiliation(s)
- Tina B McKay
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, 02114, USA
| | - Audrey E K Hutcheon
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, 02114, USA
| | - Xiaoqing Guo
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, 02114, USA
| | - James D Zieske
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA, 02114, 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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McKay TB, Schlötzer-Schrehardt U, Pal-Ghosh S, Stepp MA. Integrin: Basement membrane adhesion by corneal epithelial and endothelial cells. Exp Eye Res 2020; 198:108138. [PMID: 32712184 DOI: 10.1016/j.exer.2020.108138] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 06/30/2020] [Accepted: 07/02/2020] [Indexed: 12/11/2022]
Abstract
Integrins mediate adhesion of cells to substrates and maintain tissue integrity by facilitating mechanotransduction between cells, the extracellular matrix, and gene expression in the nucleus. Changes in integrin expression in corneal epithelial cells and corneal endothelial cells impacts their adhesion to the epithelial basement membrane (EpBM) and Descemet's membrane, respectively. Integrins also play roles in assembly of basement membranes by both activating TGFβ1 and other growth factors. Over the past two decades, this knowledge has been translated into methods to grow corneal epithelial and endothelial cells in vitro for transplantation in the clinic thereby transforming clinical practice and quality of life for patients. Current knowledge on the expression and function of the integrins that mediate adhesion to the basement membrane expressed by corneal epithelial and endothelial cells in health and disease is summarized. This is the first review to discuss similarities and differences in the integrins expressed by both cell types.
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Affiliation(s)
- Tina B McKay
- Department of Ophthalmology, Schepens Eye Research Institute / Mass Eye and Ear, 20 Staniford Street, Boston, MA, 02114, USA
| | - Ursula Schlötzer-Schrehardt
- Department of Ophthalmology, Universitätsklinikum Erlangen and Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Sonali Pal-Ghosh
- Department of Anatomy and Cell Biology, The George Washington School of Medicine and Health Sciences, Washington, DC, 20052, USA
| | - Mary Ann Stepp
- Department of Anatomy and Cell Biology, The George Washington School of Medicine and Health Sciences, Washington, DC, 20052, USA; Department of Ophthalmology, The George Washington School of Medicine and Health Sciences, Washington, DC, 20052, USA.
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17
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McKay TB, Ford A, Wang S, Cairns DM, Parker RN, Deardorff PM, Ghezzi CE, Kaplan DL. Assembly and Application of a Three-Dimensional Human Corneal Tissue Model. ACTA ACUST UNITED AC 2020; 81:e84. [PMID: 31529796 DOI: 10.1002/cptx.84] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The cornea provides a functional barrier separating the outside environment from the intraocular environment, thereby protecting posterior segments of the eye from infection and damage. Pathological changes that compromise the structure or integrity of the cornea may occur as a result of injury or disease and can lead to debilitating effects on visual acuity. Over 10 million people worldwide are visually impaired or blind due to corneal opacity. Thus, physiologically relevant in vitro approaches to predict corneal toxicity of chemicals or effective treatments for disease prior to ocular exposure, as well as to study the corneal effects of systemic, chronic conditions, such as diabetes, are needed to reduce use of animal testing and accelerate therapeutic development. We have previously bioengineered an innervated corneal tissue model using silk protein scaffolds to recapitulate the structural and mechanical elements of the anterior cornea and to model the functional aspects of corneal sensation with the inclusion of epithelial, stromal, and neural components. The purpose of this unit is to provide a step-by-step guide for preparation, assembly, and application of this three-dimensional corneal tissue system to enable the study of corneal tissue biology. © 2019 by John Wiley & Sons, Inc.
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Affiliation(s)
- Tina B McKay
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - Andrew Ford
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - Siran Wang
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - Dana M Cairns
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - Rachael N Parker
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - Phillip M Deardorff
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - Chiara E Ghezzi
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts
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McKay TB, Hutcheon AEK, Zieske JD, Ciolino JB. Extracellular Vesicles Secreted by Corneal Epithelial Cells Promote Myofibroblast Differentiation. Cells 2020; 9:cells9051080. [PMID: 32357574 PMCID: PMC7290736 DOI: 10.3390/cells9051080] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 04/20/2020] [Accepted: 04/24/2020] [Indexed: 12/13/2022] Open
Abstract
The corneal epithelium mediates the initial response to injury of the ocular surface and secretes a number of profibrotic factors that promote corneal scar development within the stroma. Previous studies have shown that corneal epithelial cells also secrete small extracellular vesicles (EVs) in response to corneal wounding. In this paper, we hypothesized that EVs released from corneal epithelial cells in vitro contain protein cargo that promotes myofibroblast differentiation, the key cell responsible for scar development. We focused on the interplay between corneal epithelial-derived EVs and the stroma to determine if the corneal fibroblast phenotype, contraction, proliferation, or migration were promoted following vesicle uptake by corneal fibroblasts. Our results showed an increase in myofibroblast differentiation based on α-smooth muscle actin expression and elevated contractility following EV treatment compared to controls. Furthermore, we characterized the contents of epithelial cell-derived EVs using proteomic analysis and identified the presence of provisional matrix proteins, fibronectin and thrombospondin-1, as the dominant encapsulated protein cargo secreted by corneal epithelial cells in vitro. Proteins associated with the regulation of protein translation were also abundant in EVs. This paper reveals a novel role and function of EVs secreted by the corneal epithelium that may contribute to corneal scarring.
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Parker RN, Wu WA, McKay TB, Xu Q, Kaplan DL. Design of Silk-Elastin-Like Protein Nanoparticle Systems with Mucoadhesive Properties. J Funct Biomater 2019; 10:E49. [PMID: 31726786 PMCID: PMC6963467 DOI: 10.3390/jfb10040049] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 11/01/2019] [Accepted: 11/06/2019] [Indexed: 12/13/2022] Open
Abstract
Transmucosal drug delivery is a promising avenue to improve therapeutic efficacy through localized therapeutic administration. Drug delivery systems that increase retention in the mucosal layer are needed to improve efficiency of such transmucosal platforms. However, the applicability of such systems is often limited by the range of chemistries and properties that can be achieved. Here we present the design and implementation of silk-elastin-like proteins (SELPs) with mucoadhesive properties. SELP-based micellar-like nanoparticles provide a system to tailor chemical and physical properties through genetic engineering of the SELP sequence, which enables the fabrication of nanoparticles with specific chemical and physical features. Analysis of the adhesion of four different SELP-based nanoparticle systems in an artificial mucus system, as well as in in vitro cellular assays indicates that addition of mucoadhesive chemical features on the SELP systems increases retention of the particles in mucosal environments. The results indicated that SELP-based nanoparticles provide a useful approach to study and develop transmucosal protein drug delivery system with unique mucoadhesive properties. Future studies will serve to further expand the range of achievable properties, as well as the utilization of SELPs to fabricate mucoadhesive materials for in vivo testing.
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Affiliation(s)
| | | | | | | | - David L. Kaplan
- Department of Biomedical Engineering, Tufts University, Medford, OR 02155, USA; (R.N.P.); (W.A.W.); (T.B.M.); (Q.X.)
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McKay TB, Priyadarsini S, Karamichos D. Mechanisms of Collagen Crosslinking in Diabetes and Keratoconus. Cells 2019; 8:cells8101239. [PMID: 31614631 PMCID: PMC6830090 DOI: 10.3390/cells8101239] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/09/2019] [Accepted: 10/10/2019] [Indexed: 12/14/2022] Open
Abstract
Collagen crosslinking provides the mechanical strength required for physiological maintenance of the extracellular matrix in most tissues in the human body, including the cornea. Aging and diabetes mellitus (DM) are processes that are both associated with increased collagen crosslinking that leads to increased corneal rigidity. By contrast, keratoconus (KC) is a corneal thinning disease associated with decreased mechanical stiffness leading to ectasia of the central cornea. Studies have suggested that crosslinking mediated by reactive advanced glycation end products during DM may protect the cornea from KC development. Parallel to this hypothesis, riboflavin-mediated photoreactive corneal crosslinking has been proposed as a therapeutic option to halt the progression of corneal thinning by inducing intra- and intermolecular crosslink formation within the collagen fibrils of the stroma, leading to stabilization of the disease. Here, we review the pathobiology of DM and KC in the context of corneal structure, the epidemiology behind the inverse correlation of DM and KC development, and the chemical mechanisms of lysyl oxidase-mediated crosslinking, advanced glycation end product-mediated crosslinking, and photoreactive riboflavin-mediated corneal crosslinking. The goal of this review is to define the biological and chemical pathways important in physiological and pathological processes related to collagen crosslinking in DM and KC.
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Affiliation(s)
- Tina B McKay
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
| | - Shrestha Priyadarsini
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Science Center, Oklahoma City, OK 73104, USA.
| | - Dimitrios Karamichos
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Science Center, Oklahoma City, OK 73104, USA.
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21
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McKay TB, Parker RN, Hawker MJ, McGill M, Kaplan DL. Silk-Based Therapeutics Targeting Pseudomonas aeruginosa. J Funct Biomater 2019; 10:jfb10030041. [PMID: 31540233 PMCID: PMC6787730 DOI: 10.3390/jfb10030041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/10/2019] [Accepted: 09/11/2019] [Indexed: 11/16/2022] Open
Abstract
Pseudomonas aeruginosa (P. aeruginosa) infections may lead to severe damage of the cornea, mucosa, and skin. The highly aggressive nature of P. aeruginosa and the rise in multi-drug resistance, particularly in nosocomial settings, lead to an increased risk for permanent tissue damage and potentially death. Thus, a growing need exists to develop alternative treatments to reduce both the occurrence of bacterial infection and biofilm development, as well as pathological progression post-infection. Silk derived from Bombyx mori silkworms serves as a unique biomaterial that is biocompatible with low immunogenicity and high versatility, and thereby ideal for stabilizing therapeutics. In this study, we assessed the cytotoxicity of P. aeruginosa on human corneal stromal stem cells and two mucosal cell lines (Caco-2 and HT29-MTX). To determine whether antibiotic-immobilized scaffolds can serve as alternative therapeutics to free, diffuse forms, we developed novel gentamicin-conjugated silk films as functional scaffolds and compared antimicrobial effects and free gentamicin. The advantages of generating a surface coating with a covalently-bound antibiotic may reduce potential side-effects associated with free gentamicin, as well as limit the diffusion of the drug. Our results suggest that gentamicin conjugated to native silk and carboxyl-enriched silk inhibits P. aeruginosa growth. Development of stabilized antibiotic treatments with surface toxicity selective against bacteria may serve as an alternative approach to treat active infections, as well as potential prophylactic use as coatings in high-risk cases, such as post-surgical complications or prolonged hospitalization.
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Affiliation(s)
- Tina B McKay
- Department of Biomedical Engineering, Tufts University, 4 Colby St, Medford, MA 02155, USA.
| | - Rachael N Parker
- Department of Biomedical Engineering, Tufts University, 4 Colby St, Medford, MA 02155, USA.
| | - Morgan J Hawker
- Department of Biomedical Engineering, Tufts University, 4 Colby St, Medford, MA 02155, USA.
| | - Meghan McGill
- Department of Biomedical Engineering, Tufts University, 4 Colby St, Medford, MA 02155, USA.
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, 4 Colby St, Medford, MA 02155, USA.
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McKay TB, Seyed-Razavi Y, Ghezzi CE, Dieckmann G, Nieland TJF, Cairns DM, Pollard RE, Hamrah P, Kaplan DL. Corneal pain and experimental model development. Prog Retin Eye Res 2019; 71:88-113. [PMID: 30453079 PMCID: PMC6690397 DOI: 10.1016/j.preteyeres.2018.11.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 11/03/2018] [Accepted: 11/13/2018] [Indexed: 12/13/2022]
Abstract
The cornea is a valuable tissue for studying peripheral sensory nerve structure and regeneration due to its avascularity, transparency, and dense innervation. Somatosensory innervation of the cornea serves to identify changes in environmental stimuli at the ocular surface, thereby promoting barrier function to protect the eye against injury or infection. Due to regulatory demands to screen ocular safety of potential chemical exposure, a need remains to develop functional human tissue models to predict ocular damage and pain using in vitro-based systems to increase throughput and minimize animal use. In this review, we summarize the anatomical and functional roles of corneal innervation in propagation of sensory input, corneal neuropathies associated with pain, and the status of current in vivo and in vitro models. Emphasis is placed on tissue engineering approaches to study the human corneal pain response in vitro with integration of proper cell types, controlled microenvironment, and high-throughput readouts to predict pain induction. Further developments in this field will aid in defining molecular signatures to distinguish acute and chronic pain triggers based on the immune response and epithelial, stromal, and neuronal interactions that occur at the ocular surface that lead to functional outcomes in the brain depending on severity and persistence of the stimulus.
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Affiliation(s)
- Tina B McKay
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Yashar Seyed-Razavi
- Center for Translational Ocular Immunology and Cornea Service, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
| | - Chiara E Ghezzi
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Gabriela Dieckmann
- Center for Translational Ocular Immunology and Cornea Service, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
| | - Thomas J F Nieland
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Dana M Cairns
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Rachel E Pollard
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Pedram Hamrah
- Center for Translational Ocular Immunology and Cornea Service, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA.
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Deardorff PM, McKay TB, Wang S, Ghezzi CE, Cairns DM, Abbott RD, Funderburgh JL, Kenyon KR, Kaplan DL. Modeling Diabetic Corneal Neuropathy in a 3D In Vitro Cornea System. Sci Rep 2018; 8:17294. [PMID: 30470798 PMCID: PMC6251923 DOI: 10.1038/s41598-018-35917-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 10/31/2018] [Indexed: 12/13/2022] Open
Abstract
Diabetes mellitus is a disease caused by innate or acquired insulin deficiency, resulting in altered glucose metabolism and high blood glucose levels. Chronic hyperglycemia is linked to development of several ocular pathologies affecting the anterior segment, including diabetic corneal neuropathy and keratopathy, neovascular glaucoma, edema, and cataracts leading to significant visual defects. Due to increasing disease prevalence, related medical care costs, and visual impairment resulting from diabetes, a need has arisen to devise alternative systems to study molecular mechanisms involved in disease onset and progression. In our current study, we applied a novel 3D in vitro model of the human cornea comprising of epithelial, stromal, and neuronal components cultured in silk scaffolds to study the pathological effects of hyperglycemia on development of diabetic corneal neuropathy. Specifically, exposure to sustained levels of high glucose, ranging from 35 mM to 45 mM, were applied to determine concentration-dependent effects on nerve morphology, length and density of axons, and expression of metabolic enzymes involved in glucose metabolism. By comparing these metrics to in vivo studies, we have developed a functional 3D in vitro model for diabetic corneal neuropathy as a means to investigate corneal pathophysiology resulting from prolonged exposure to hyperglycemia.
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Affiliation(s)
- Phillip M Deardorff
- Department of Biomedical Engineering, Tufts University, Medford, MA, 02155, USA
| | - Tina B McKay
- Department of Biomedical Engineering, Tufts University, Medford, MA, 02155, USA
| | - Siran Wang
- Department of Biomedical Engineering, Tufts University, Medford, MA, 02155, USA
| | - Chiara E Ghezzi
- Department of Biomedical Engineering, Tufts University, Medford, MA, 02155, USA
| | - Dana M Cairns
- Department of Biomedical Engineering, Tufts University, Medford, MA, 02155, USA
| | - Rosalyn D Abbott
- Department of Biomedical Engineering, Tufts University, Medford, MA, 02155, USA
| | - James L Funderburgh
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Kenneth R Kenyon
- Department of Ophthalmology, Tufts New England Medical Center, Boston, MA, USA
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, Medford, MA, 02155, USA.
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Siran W, Ghezzi CE, Cairns DM, Pollard RE, Chen Y, Gomes R, McKay TB, Pouli D, Jamali A, Georgakoudi I, Funderburgh JL, Kenyon K, Hamrah P, Kaplan DL. Human Corneal Tissue Model for Nociceptive Assessments. Adv Healthc Mater 2018; 7:e1800488. [PMID: 30091220 DOI: 10.1002/adhm.201800488] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 06/28/2018] [Indexed: 12/13/2022]
Abstract
New in vitro tissue models to mimic in vivo conditions are needed to provide insight into mechanisms involved in peripheral pain responses, potential therapeutic strategies to address these responses, and to replace animal models for such indications. For example, the rabbit cornea Draize test has become the standard method used for decades to screen ophthalmic drug and consumer product toxicity. In vitro tissue models with functional innervation have the potential to replace in vivo animal testing and provide sophisticated bench tools to study ocular nociception and its amelioration. Herein, full thickness, innervated, 3D human corneal tissues are grown under physiologically relevant culture conditions to study nociceptive-related responses, by mimicking ocular environmental cues, including intraocular pressure (IOP) and tear flow (TF). Capsaicin, a chili pepper-derived irritant known to cause a burning sensation in mammalian tissues is utilized as a nociceptive stimulant to induce pain, while subsequent serum treatment is used to mimic healing. Pain mediators released upon capsaicin stimulation and cell regrowth after serum treatment are characterized to assess ocular responses in this new, innervated, human corneal tissue system for comparison of outcomes to established animal and related responses.
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Affiliation(s)
- Wang Siran
- Department of Biomedical EngineeringTufts University 4 Colby Street Medford MA 02155 USA
| | - Chiara E. Ghezzi
- Department of Biomedical EngineeringTufts University 4 Colby Street Medford MA 02155 USA
| | - Dana M. Cairns
- Department of Biomedical EngineeringTufts University 4 Colby Street Medford MA 02155 USA
| | - Rachel E. Pollard
- Department of Biomedical EngineeringTufts University 4 Colby Street Medford MA 02155 USA
| | - Ying Chen
- Department of Biomedical EngineeringTufts University 4 Colby Street Medford MA 02155 USA
| | - Rachel Gomes
- Department of Biomedical EngineeringTufts University 4 Colby Street Medford MA 02155 USA
- School of MedicineDepartamento de Oftalmologia da Escola Paulista de MedicinaFederal University of São Paulo Botucatu, 822 – Vila Clementino São Paulo –SP 04023‐062 Brazil
| | - Tina B. McKay
- Department of Biomedical EngineeringTufts University 4 Colby Street Medford MA 02155 USA
| | - Dimitra Pouli
- Department of Biomedical EngineeringTufts University 4 Colby Street Medford MA 02155 USA
| | - Arsia Jamali
- New England Eye CenterTufts Medical Center 260 Tremont St, 9th Floor Boston MA 02111 USA
| | - Irene Georgakoudi
- Department of Biomedical EngineeringTufts University 4 Colby Street Medford MA 02155 USA
| | - James L. Funderburgh
- Eye & Ear InstituteDepartment of OphthalmologyUniversity of Pittsburgh 203 Lothrop Street, Room 1011 Pittsburgh PA 15213 USA
| | - Kenneth Kenyon
- New England Eye CenterTufts Medical Center 260 Tremont St, 9th Floor Boston MA 02111 USA
| | - Pedram Hamrah
- New England Eye CenterTufts Medical Center 260 Tremont St, 9th Floor Boston MA 02111 USA
| | - David L. Kaplan
- Department of Biomedical EngineeringTufts University 4 Colby Street Medford MA 02155 USA
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McKay TB, Hjortdal J, Priyadarsini S, Karamichos D. Acute hypoxia influences collagen and matrix metalloproteinase expression by human keratoconus cells in vitro. PLoS One 2017; 12:e0176017. [PMID: 28426715 PMCID: PMC5398580 DOI: 10.1371/journal.pone.0176017] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 04/04/2017] [Indexed: 01/10/2023] Open
Abstract
Keratoconus (KC) is a progressive corneal ectasia linked to thinning of the central cornea. Hard contact lenses, rigid gas permeable lenses, and scleral lenses are the primary treatment modalities for early to mid- stages of KC to correct refractive error and astigmatism that develops as a result of an irregular corneal structure. These treatments are associated with significant drawbacks, including reduced availability of the tear film and oxygen to the corneal epithelium and stroma. However, it remains unknown whether hypoxia affects corneal integrity in the KC pathobiology. A number of studies have associated elevated oxidative stress with KC both in vitro and ex vivo. We hypothesized that KC-derived corneal fibroblasts are more susceptible to hypoxia-induced oxidative stress compared to healthy controls leading to exacerbation of corneal thinning in KC. This study investigated the effects of hypoxia on ECM secretion, assembly, and matrix metalloproteinase (MMP) expression in human corneal fibroblasts from healthy controls (HCFs) and KC patients (HKCs) in vitro. HCFs and HKCs were cultured in 3D constructs for 3 weeks and maintained or transferred to normoxic (21% O2) or hypoxic (2% O2) conditions, respectively, for 1 additional week. At the 4 week time-point, constructs were isolated and probed for Collagen I, III, and V, keratocan and MMP-1, -2, -3, -9, and -13, as well as hypoxia markers, hypoxia inducible factor-1α and lactoferrin. Conditioned media was also collected and probed for Collagen I, III, and V by Western blot. Thickness of the ECM assembled by HCFs and HKCs was measured using immunofluorescence microscopy. Results showed that hypoxia significantly reduced Collagen I secretion in HKCs, as well as upregulated the expression of MMP-1 and -2 with no significant effects on MMP-3, -9, or -13. ECM thickness was reduced in both cell types following 1 week in a low oxygen environment. Our study shows that hypoxia influences collagen and MMP expression by HKCs, which may have consequential effects on ECM structure in the context of KC.
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Affiliation(s)
- Tina B. McKay
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Jesper Hjortdal
- Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark
| | - Shrestha Priyadarsini
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Dimitrios Karamichos
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
- * E-mail:
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Abstract
Flavonoids are a class of plant and fungus secondary metabolites that serve functional roles in protecting against UV-induced oxidative stress, mediating auxin signaling, and promoting microbial defense. Flavonoids are extremely abundant in nature where their potent antioxidant capacity and very low toxicity makes them highly attractive as potential therapeutic agents. In terms of clinical applications, neither the Food and Drug Administration (FDA) nor the European Food Safety Authority (EFSA) has approved any health claims or drugs related to the use of flavonoids for therapeutic purposes. Quercetin is a common flavonol that has been shown to have potent antioxidant, anti-inflammatory, and anti-fibrotic activities both in vitro and in vivo in various tissues. Recently, the application of quercetin as a therapeutic has been gaining attention in the ocular surface scientific community in the study of dry eye, keratoconus, inflammation, and neovascularization of the cornea. This review will discuss the latest findings and the use of quercetin for the treatment of dystrophies of the ocular surface. Impact statement The eye represents a small portion of the human body, accounting for one decimal fraction of the anterior body surface. The cornea is an avascular, transparent tissue that acts as a primary barrier against mechanical and infectious damaging agents, protecting the internal structures of the eye. Corneal survival and function are affected by a number of factors including but not limited to injury, trauma, infection, genetics, and environment. Corneal injury, or trauma, often leads to loss of corneal transparency and even blindness. The concept of "curing" corneal opacity has been discussed in published form for over 200 years. Currently, full corneal transplant is the only treatment option. There is a strong interest in developing natural therapeutic products that come with minimum side effects. A novel antioxidant flavonoid, quercetin, has been gaining traction as a potential therapeutic to prevent the injured cornea. This review discusses the potential of this antioxidant.
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Affiliation(s)
- Tina B McKay
- 1 Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104,USA
| | - Dimitrios Karamichos
- 1 Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104,USA.,2 Department of Ophthalmology, Dean McGee Eye Institute, Oklahoma City, OK 73104, USA
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Priyadarsini S, McKay TB, Sarker-Nag A, Allegood J, Chalfant C, Ma JX, Karamichos D. Complete metabolome and lipidome analysis reveals novel biomarkers in the human diabetic corneal stroma. Exp Eye Res 2016; 153:90-100. [PMID: 27742548 DOI: 10.1016/j.exer.2016.10.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/03/2016] [Accepted: 10/07/2016] [Indexed: 01/05/2023]
Abstract
Prolonged hyperglycemia during diabetes mellitus can cause severe ophthalmic complications affecting both the anterior and posterior ocular segments leading to impaired vision or blindness. Diabetes-induced corneal pathologies are associated with decreased wound healing capacity, corneal edema, and altered epithelial basement membrane. The mechanism by which diabetes modulates structure and function within the corneal stroma are unknown. In our study, we characterized the effects of diabetes on extracellular matrix, lipid transport, and cellular metabolism by defining the entire metabolome and lipidome of Type 1 and Type 2 human diabetic corneal stroma. Significant increases in Collagen I and III were found in diabetic corneas suggesting that diabetes promotes defects in matrix structure leading to scarring. Furthermore, increased lipid content, including sphingosine-1-phosphate and dihydrosphingosine, in diabetic corneas compared to healthy controls were measured suggesting altered lipid retention. Metabolomics analysis identified elevated tryptophan metabolites, independent of glucose metabolism, which correlated with upregulation of the Kynurenine pathway in diabetic corneas. We also found significant upregulation of novel biomarkers aminoadipic acid, D,L-pipecolic acid, and dihydroorotate. Our study links aberrant tryptophan metabolism to end-stage pathologies associated with diabetes indicating the potential of the Kynurenine pathway as a therapeutic target for inhibiting diabetes-associated defects in the eye.
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Affiliation(s)
- Shrestha Priyadarsini
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Tina B McKay
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Akhee Sarker-Nag
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Jeremy Allegood
- Hunter Holmes McGuire Veterans Administration Medical Center, Richmond, VA, USA; Department of Biochemistry and Molecular Biology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA; The VCU Johnson Center, Richmond, VA, USA; The VCU Massey Cancer Center, Richmond, VA, USA
| | - Charles Chalfant
- Hunter Holmes McGuire Veterans Administration Medical Center, Richmond, VA, USA; Department of Biochemistry and Molecular Biology, School of Medicine, Virginia Commonwealth University, Richmond, VA, USA; The VCU Johnson Center, Richmond, VA, USA; The VCU Massey Cancer Center, Richmond, VA, USA
| | - Jian-Xing Ma
- Department of Physiology Harold Hamm Diabetes Center, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Dimitrios Karamichos
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA; Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
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McKay TB, Hjortdal J, Sejersen H, Asara JM, Wu J, Karamichos D. Endocrine and Metabolic Pathways Linked to Keratoconus: Implications for the Role of Hormones in the Stromal Microenvironment. Sci Rep 2016; 6:25534. [PMID: 27157003 PMCID: PMC4860577 DOI: 10.1038/srep25534] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 04/19/2016] [Indexed: 12/17/2022] Open
Abstract
Hormones play a critical role in regulating tissue function by promoting cell survival, proliferation, and differentiation. Our study explores the influence of endocrine function in regulating metabolism and inflammatory pathways in Keratoconus (KC), which is a corneal thinning disease associated with reduced stromal deposition. KC is known to be a multifactorial disease with an elusive pathogenesis. We utilized a cross-sectional study analyzing clinical features and saliva samples from sixty-four KC patients and fourteen healthy controls. In order to determine if endocrine function varied between healthy controls and KC, we measured hormone levels in saliva and found significantly increased dehydroepiandrosterone sulfate (DHEA-S) and reduced estrone levels in KC patients compared to healthy controls. We measured significant variations in metabolites associated with pro-inflammatory processes, including myoinositol and 1-methyl-histidine, by targeted mass spectrometry. We also measured significantly increased IL-16 and stem cell factor in KC saliva samples compared to healthy controls, with higher expression of these pro-inflammatory proteins correlating with increased KC clinical grade, corneal curvature, and stromal thinning. Our results identify a novel mechanism linking KC and pro-inflammatory markers and suggest that altered hormone levels modulate metabolism, cytokine, and growth factor expression leading to increased severity of the KC condition.
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Affiliation(s)
- Tina B McKay
- Department of Cell Biology/ University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Jesper Hjortdal
- Department of Ophthalmology, Aarhus University Hospital, Aarhus C DK-8000, Denmark
| | - Henrik Sejersen
- Department of Ophthalmology, Aarhus University Hospital, Aarhus C DK-8000, Denmark
| | - John M Asara
- Division of Signal Transduction, Beth Israel Deaconess Medical and Department of Medicine, Harvard Medical School, Boston, MA USA
| | - Jennifer Wu
- Department of Ophthalmology/Dean McGee Eye Institute, Oklahoma City, OK 73104, USA
| | - Dimitrios Karamichos
- Department of Cell Biology/ University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.,Department of Ophthalmology/Dean McGee Eye Institute, Oklahoma City, OK 73104, USA
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McKay TB, Sarker-Nag A, Lyon D, Asara JM, Karamichos D. Quercetin modulates keratoconus metabolism in vitro. Cell Biochem Funct 2015; 33:341-50. [PMID: 26173740 DOI: 10.1002/cbf.3122] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 05/15/2015] [Accepted: 05/19/2015] [Indexed: 12/12/2022]
Abstract
Corneal scarring is the result of a disease, infection or injury. The resulting scars cause significant loss of vision or even blindness. To-date, the most successful treatment is corneal transplantation, but it does not come without side effects. One of the corneal dystrophies that are correlated with corneal scarring is keratoconus (KC). The onset of the disease is still unknown; however, altered cellular metabolism has been linked to promoting the fibrotic phenotype and therefore scarring. We have previously shown that human keratoconus cells (HKCs) have altered metabolic activity when compared to normal human corneal fibroblasts (HCFs). In our current study, we present evidence that quercetin, a natural flavonoid, is a strong candidate for regulating metabolic activity of both HCFs and HKCs in vitro and therefore a potential therapeutic to target the altered cellular metabolism characteristic of HKCs. Targeted mass spectrometry-based metabolomics was performed on HCFs and HKCs with and without quercetin treatment in order to identify variations in metabolite flux. Overall, our study reveals a novel therapeutic target OF Quercetin on corneal stromal cell metabolism in both healthy and diseased states. Clearly, further studies are necessary in order to dissect the mechanism of action of quercetin.
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Affiliation(s)
- Tina B McKay
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Akhee Sarker-Nag
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Desiree' Lyon
- Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - John M Asara
- Division of Signal Transduction, Beth Israel Deaconess Medical Center and Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Dimitrios Karamichos
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Department of Ophthalmology/Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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