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Yildiz P, Kebapci MN, Colak E, Mutlu F, Simsek T, Yildirim N. Relationship between hyperglycemia and intraocular pressure, corneal biomechanics, and corneal topography during the oral glucose tolerance test in nondiabetic patients. Int Ophthalmol 2024; 44:347. [PMID: 39138825 DOI: 10.1007/s10792-024-03264-w] [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: 03/08/2023] [Accepted: 07/29/2024] [Indexed: 08/15/2024]
Abstract
PURPOSE Altered corneal biomechanics in patients with diabetes may affect intraocular pressure (IOP) measurements. Although a relationship between IOP and glucose levels has been reported in diabetic and nondiabetic patients, the mechanism by which hyperglycemia influences IOP is unclear. The aim of this study was to determine the effects of hyperglycemia on IOP, corneal biomechanics, and anterior segment parameters during the oral glucose tolerance test (OGTT) in nondiabetic patients. METHODS Twenty-one patients without DM who underwent OGTT were included in this study. A complete ophthalmologic examination was performed before the test. Blood glucose, insulin level, IOP (iCare rebound tonometer), Ocular Response Analyzer, and corneal topography (Pentacam) measurements were obtained at 0, 1, and 2 h during the OGTT. Data from the patients' right eyes were included in the analysis. RESULTS The mean age of the patients was 46.9 ± 11.0 years. There was a statistically significant difference in IOP between 1 and 2 h (p = 0.03) and a clinically significant difference between 0 and 1 h (p = 0.06). Corneal resistance factor was lower at 2 h than 1 h (p = 0.03), while central cornea thickness was increased at 1 h (p = 0.01) and 2 h (p = 0.05) compared to 0 h. There was positive partial correlation between hyperglycemia and IOP at 1 h (p = 0.049, r = 0.67). CONCLUSION The positive partial correlation between IOP and glucose level suggests that acute hyperglycemia may lead to increased IOP. However, further research is needed to explain the mechanism of IOP elevation in the hyperglycemic phase during OGTT.
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Affiliation(s)
- Pinar Yildiz
- Department of Internal Medicine, Eskişehir Osmangazi University, Eskişehir, Turkey.
| | - Medine Nur Kebapci
- Department of Internal Medicine, Eskişehir Osmangazi University, Eskişehir, Turkey
| | - Ertugrul Colak
- Department of Biostatistics, Eskişehir Osmangazi University, Eskisehir, Turkey
| | - Fezan Mutlu
- Department of Biostatistics, Eskişehir Osmangazi University, Eskisehir, Turkey
| | - Tulay Simsek
- Department of Ophthalmology, Eskişehir Osmangazi University, Eskisehir, Turkey
| | - Nilgun Yildirim
- Department of Ophthalmology, Eskişehir Osmangazi University, Eskisehir, Turkey
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Şahin R, Aslan MG. Corneal aberrations are associated with low-energy meniscus injuries. BMC Ophthalmol 2024; 24:328. [PMID: 39107739 PMCID: PMC11302090 DOI: 10.1186/s12886-024-03601-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 07/30/2024] [Indexed: 08/10/2024] Open
Abstract
BACKGROUND Visual impairment can cause balance problems. Therefore, visual impairment caused by an increase in corneal deviations can lead to sudden and unstable loads in the lower extremities. We aimed to investigate the possible relationship between low-energy meniscal injuries and corneal structural measures. METHODS This prospective, observational study included individuals aged between 18-40 years with a normal body-mass index. The study group consisted of 54 patients with grade 2 or 3 meniscus injuries after low-energy activity. The control group consisted of 54 healthy individuals without any complaints in the knee joint. The corneal parameters of all participants were evaluated with a Scheimpflug corneal topography and specular microscopy device. Simulated keratometry (SimK), minimum central corneal thickness (MCCT), cylindrical diopter (ClyD), corneal volume (CVol) spheric aberrations (SphAbb), high-order aberration (HOA), coma values, and endothelial parameters were recorded. RESULTS The research and control groups were similar in terms of age, body mass index, and gender distribution. There was no significant difference between the groups in the corneal SimK and CylD, parameters. However, HOA, Coma, SphAbb, and cell variability (Cv) values were significantly higher in the study group, and contrarily MCCT, CVol, and endothelial count (Cd) values were significantly lower. CONCLUSIONS Our findings suggest that individuals with relatively lower MCCT values tend to develop meniscal damage after low-energy activity. Hence, the loss of corneal strength in these patients may be a sign of possible weakness in the meniscus. The HOA value above 0.26, the coma value above 0.16, and the SphAbb value above 0.1 may significantly increase the possible meniscus injury.
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Affiliation(s)
- Rıfat Şahin
- Department of Orthopaedia and Traumatology, Faculty of Medicine, Recep Tayyip Erdogan University, İslampaşa Mah., Şehitler Cad., No:74, Zipcode: 53020, Merkez, Rize, Turkey.
| | - Mehmet Gökhan Aslan
- Department of Ophthalmology, Faculty of Medicine, Recep Tayyip Erdogan University, Rize, Turkey
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Mukunda DC, Basha S, D'Souza MG, Chandra S, Ameera K, Stanley W, Mazumder N, Mahato KK. Label-free visualization of unfolding and crosslinking mediated protein aggregation in nonenzymatically glycated proteins. Analyst 2024; 149:4029-4040. [PMID: 38963259 DOI: 10.1039/d4an00358f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Nonenzymatic glycation (NEG) unfolds and crosslinks proteins, resulting in aggregation. Label-free evaluation of such structural changes, without disturbing molecular integrity, would be beneficial for understanding the fundamental mechanisms of protein aggregation. The current study demonstrates the assessment of NEG-induced protein aggregation by combining autofluorescence (AF) spectroscopy and imaging. The methylglyoxal (MG) induced protein unfolding and the formation of cross-linking advanced glycation end-products (AGEs) leading to aggregation were evaluated using deep-UV-induced-autofluorescence (dUV-AF) spectroscopy in proteins with distinct structural characteristics. Since the AGEs formed on proteins are fluorescent, the study demonstrated the possibility of autofluorescence imaging of NEG-induced protein aggregates. Autofluorescence spectroscopy can potentially reveal molecular alterations such as protein unfolding and cross-linking. In contrast, AGE-based autofluorescence imaging offers a means to visually explore the structural arrangement of aggregates, regardless of whether they are amyloid or non-amyloid in nature.
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Affiliation(s)
| | - Shaik Basha
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India.
| | - Meagan Gail D'Souza
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India.
| | - Subhash Chandra
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India.
| | - K Ameera
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India.
| | - Weena Stanley
- Department of Medicine, Kasturba Medical College, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Nirmal Mazumder
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India.
| | - Krishna Kishore Mahato
- Department of Biophysics, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal 576104, Karnataka, India.
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Ghenciu LA, Hațegan OA, Bolintineanu SL, Dănilă AI, Faur AC, Prodan-Bărbulescu C, Stoicescu ER, Iacob R, Șișu AM. Immune-Mediated Ocular Surface Disease in Diabetes Mellitus-Clinical Perspectives and Treatment: A Narrative Review. Biomedicines 2024; 12:1303. [PMID: 38927510 PMCID: PMC11201425 DOI: 10.3390/biomedicines12061303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 06/06/2024] [Accepted: 06/10/2024] [Indexed: 06/28/2024] Open
Abstract
Diabetes mellitus (DM) is a chronic metabolic disorder marked by hyperglycemia due to defects in insulin secretion, action, or both, with a global prevalence that has tripled in recent decades. This condition poses significant public health challenges, affecting individuals, healthcare systems, and economies worldwide. Among its numerous complications, ocular surface disease (OSD) is a significant concern, yet understanding its pathophysiology, diagnosis, and management remains challenging. This review aims to explore the epidemiology, pathophysiology, clinical manifestations, diagnostic approaches, and management strategies of diabetes-related OSD. The ocular surface, including the cornea, conjunctiva, and associated structures, is vital for maintaining eye health, with the lacrimal functional unit (LFU) playing a crucial role in tear film regulation. In DM, changes in glycosaminoglycan metabolism, collagen synthesis, oxygen consumption, and LFU dysfunction contribute to ocular complications. Persistent hyperglycemia leads to the expression of cytokines, chemokines, and cell adhesion molecules, resulting in neuropathy, tear film abnormalities, and epithelial lesions. Recent advances in molecular research and therapeutic modalities, such as gene and stem cell therapies, show promise for managing diabetic ocular complications. Future research should focus on pathogenetically oriented therapies for diabetic neuropathy and keratopathy, transitioning from animal models to clinical trials to improve patient outcomes.
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Affiliation(s)
- Laura Andreea Ghenciu
- Department of Functional Sciences, “Victor Babes” University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania;
| | - Ovidiu Alin Hațegan
- Discipline of Anatomy and Embriology, Medicine Faculty, ‘Vasile Goldis’ Western University of Arad, Revolution Boulevard 94, 310025 Arad, Romania
| | - Sorin Lucian Bolintineanu
- Department of Anatomy and Embriology, “Victor Babes” University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (S.L.B.); (A.-I.D.); (A.C.F.); (C.P.-B.); (R.I.); (A.M.Ș.)
| | - Alexandra-Ioana Dănilă
- Department of Anatomy and Embriology, “Victor Babes” University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (S.L.B.); (A.-I.D.); (A.C.F.); (C.P.-B.); (R.I.); (A.M.Ș.)
| | - Alexandra Corina Faur
- Department of Anatomy and Embriology, “Victor Babes” University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (S.L.B.); (A.-I.D.); (A.C.F.); (C.P.-B.); (R.I.); (A.M.Ș.)
| | - Cătălin Prodan-Bărbulescu
- Department of Anatomy and Embriology, “Victor Babes” University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (S.L.B.); (A.-I.D.); (A.C.F.); (C.P.-B.); (R.I.); (A.M.Ș.)
- Doctoral School, “Victor Babes” University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
- IInd Surgery Clinic, “Victor Babes” University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
| | - Emil Robert Stoicescu
- Field of Applied Engineering Sciences, Specialization Statistical Methods and Techniques in Health and Clinical Research, Faculty of Mechanics, ‘Politehnica’ University Timisoara, Mihai Viteazul Boulevard No. 1, 300222 Timisoara, Romania;
- Department of Radiology and Medical Imaging, “Victor Babes” University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
- Research Center for Pharmaco-Toxicological Evaluations, “Victor Babes” University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
| | - Roxana Iacob
- Department of Anatomy and Embriology, “Victor Babes” University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (S.L.B.); (A.-I.D.); (A.C.F.); (C.P.-B.); (R.I.); (A.M.Ș.)
- Doctoral School, “Victor Babes” University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
- Field of Applied Engineering Sciences, Specialization Statistical Methods and Techniques in Health and Clinical Research, Faculty of Mechanics, ‘Politehnica’ University Timisoara, Mihai Viteazul Boulevard No. 1, 300222 Timisoara, Romania;
| | - Alina Maria Șișu
- Department of Anatomy and Embriology, “Victor Babes” University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (S.L.B.); (A.-I.D.); (A.C.F.); (C.P.-B.); (R.I.); (A.M.Ș.)
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Chung IK, Kim BS, Han KD, Yoo YS, Kim H, Jeong C. Ten-year incidence of keratoconus in relation to sex, age, and thyroid gland dysfunction: a nationwide population-based cohort study (2009-2018). ANNALS OF TRANSLATIONAL MEDICINE 2024; 12:45. [PMID: 38911561 PMCID: PMC11193565 DOI: 10.21037/atm-23-1906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 03/10/2024] [Indexed: 06/25/2024]
Abstract
Background Keratoconus is a corneal ectatic disorder that often leads to visual impairment and may require corneal transplantation. However, its age and gender-based incidence and potential association with thyroid gland dysfunction (TGD) remain poorly understood. This study aims to clarify these aspects and investigate the possible connection between keratoconus and TGD. Methods We conducted a nationwide population-based cohort study using data from the Korean National Health Insurance Service database. A retrospective chart review was conducted on 4,059,021 patients aged over 20 without underlying corneal diseases in 2009. The end of the review period was at ten years, or until the onset of keratoconus. To evaluate the association with TGD, multivariate Cox regression analysis was used with adjustment of confounding variables such as sex and age. Results During the review period, 2,334 patients developed keratoconus before the 10-year mark. Females exhibited a higher keratoconus incidence (7.101 per 100,000 person-years) compared to males (5.559) (P<0.001). After adjusting for age, the hazard ratio (HR) for keratoconus was 1.295 times higher [95% confidence interval (CI): 1.193-1.406] in females compared to males. Age groups were stratified in 10-year intervals. The highest incidence of keratoconus was observed in the 20 to 29-year age group (10.695 per 100,000 person-years). All other age groups had significantly lower HR values, with the lowest at 50-59 years (0.508, 95% CI: 0.447-0.577). Keratoconus incidence per 100,000 person-years was 6.227 in subjects without TGD, 6.019 in the hypothyroidism group and 8.287 in the hyperthyroidism group, respectively. Although not statistically significant, individuals with hyperthyroidism showed a higher HR (1.290, 95% CI: 0.939-1.771) for keratoconus when compared to those without TGD, after adjusting for age and sex. Conclusions This study emphasizes a female predominance in keratoconus incidence and suggests a possible connection between hyperthyroidism and keratoconus. Furthermore, it affirms a higher incidence of keratoconus among young individuals.
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Affiliation(s)
- In Kwon Chung
- Department of Ophthalmology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, South Korea
| | - Bong-Seong Kim
- Statistics and Actuarial Science, Soongsil University, Seoul, South Korea
| | - Kyung-Do Han
- Statistics and Actuarial Science, Soongsil University, Seoul, South Korea
| | - Young-Sik Yoo
- Department of Ophthalmology, College of Medicine, Uijeongbu St. Mary’s Hospital, The Catholic University of Korea, Seoul, South Korea
| | - Hyojin Kim
- Department of Optometry, Division of Health Science, Baekseok University, Cheonan, South Korea
- Department of Optometry, Graduate School of Christian Studies, Baekseok University, Seoul, South Korea
| | - Chaiho Jeong
- Department of Internal Medicine, College of Medicine, Uijeongbu St. Mary’s Hospital, The Catholic University of Korea, Seoul, South Korea
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Ge LY, Wu TH, Liu YQ, Jiang C, Yin X. Management of experimental trabeculectomy filtering blebs via crosslinking of the scleral flap inhibited vascularization. Graefes Arch Clin Exp Ophthalmol 2024; 262:1507-1517. [PMID: 37943331 DOI: 10.1007/s00417-023-06306-8] [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: 06/27/2023] [Revised: 10/10/2023] [Accepted: 10/23/2023] [Indexed: 11/10/2023] Open
Abstract
PURPOSE The aim of this study was to evaluate whether UVA-light-activated riboflavin-induced collagen crosslinking (UVA-CXL) can maintain the function of filtering blebs after trabeculectomy (TRAB) in rabbits. METHODS Thirty-six healthy rabbits were randomized to one of the following groups with 12 rabbits in each group: Trabeculectomy group (TRAB group), trabeculectomy combined with CXL group (CXL group), and trabeculectomy combined with MMC group (MMC group). Six rabbits of each group were performed with intraocular pressure (IOP), optical coherence tomography (OCT), and OCT angiography (OCTA). Bleb structure was observed via hematoxylin & eosin (H&E) and Masson staining. Immunohistochemistry, proteomic study, western blot, and tensile test were performed between CXL group and the control. In vitro, cell viability was evaluated by CCK-8 and Calcein/PI staining. TRPV4 and VEGF-a expression levels were measured by Q-PCR. Ca2+ concentration was observed with Fluo-4 AM. RESULTS The IOP and bleb median survival day were significantly modified in CXL (5.92 ± 0.32 mmHg and 15.5 days) than TRAB group (7.50 ± 0.43 mmHg and 9 days). The bleb area and height increased. CXL inhibited vascularization, and vascularization peaked at postoperative day (POD) 14 and then decreased gradually. In proteomic analyses, Z disc, actin filament binding, and sarcomere organization were significantly enriched. CXL inhibited scleral stress‒strain in tensile tests. Compared with TRAB group, TRPV4 expression was significantly increased, but VEGF-a and TGF-β1 levels were reduced in the CXL group in western blot. Meanwhile, TRPV4 expression colocalized with CD31. In vitro, CXL inhibited HUVECs cell viability. After CXL, expression level of TRPV4 was increased and calcium influx was activated, but VEGF-a was decreased in HUVECs. CONCLUSIONS This study demonstrates that intraoperative UV-RF CXL can significantly improve the success rate of TRAB via inhibiting filtering bleb vascularization. CXL increased sclera stiffness, in turn, induced TRPV4 activation, thus contributing to vascular endothelial cells suppression.
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Affiliation(s)
- Ling Ying Ge
- Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Shizi Street 188, Suzhou, 21006, Jiangsu Province, China
| | - Tian Hong Wu
- Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Shizi Street 188, Suzhou, 21006, Jiangsu Province, China
| | - Yue Qi Liu
- Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Shizi Street 188, Suzhou, 21006, Jiangsu Province, China
| | - Chun Jiang
- Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Shizi Street 188, Suzhou, 21006, Jiangsu Province, China
| | - Xue Yin
- Department of Ophthalmology, the First Affiliated Hospital of Soochow University, Shizi Street 188, Suzhou, 21006, Jiangsu Province, China.
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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. OPHTHALMOLOGY SCIENCE 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] [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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Chai N, Stachon T, Berger T, Li Z, Seitz B, Langenbucher A, Szentmáry N. Short-Term Effect of Rose Bengal Photodynamic Therapy (RB-PDT) on Collagen I, Collagen V, NF-κB, LOX, TGF-β and IL-6 Expression of Human Corneal Fibroblasts, In Vitro. Curr Eye Res 2024; 49:150-157. [PMID: 37921272 DOI: 10.1080/02713683.2023.2276057] [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: 07/31/2023] [Accepted: 10/24/2023] [Indexed: 11/04/2023]
Abstract
PURPOSE To investigate collagen I, collagen V, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), lysyl oxidase (LOX), transforming growth factor β1 (TGF-β1) and interleukin-6 (IL-6) expression in healthy and keratoconus human corneal fibroblasts (HCFs and KC-HCFs), 24 h after Rose Bengal photodynamic therapy (RB-PDT). METHODS HCFs were isolated from healthy human corneal donors (n = 5) and KC-HCFs from elective penetrating keratoplasties (n = 5). Both cell cultures underwent RB-PDT (0.001% RB concentration, 0.17 J/cm2 fluence) and 24 h later collagen I, collagen V, NF-κB, LOX, TGF-β1 and IL-6 mRNA and protein expression have been determined using qPCR and Western blot, IL-6 concentration in the cell culture supernatant by ELISA. RESULTS TGF-β1 mRNA expression was significantly lower (p = 0.02) and IL-6 mRNA expression was significantly higher in RB-PDT treated HCFs (p = 0.01), than in HCF controls. COL1A1, COL5A1 and TGF-β1 mRNA expression was significantly lower (p = 0.04; p = 0.02 and p = 0.003) and IL-6 mRNA expression was significantly higher (p = 0.02) in treated KC-HCFs, than in KC-HCF controls. TGF-β1 protein expression in treated HCFs was significantly higher than in HCF controls (p = 0.04). IL-6 protein concentration in the HCF and KC-HCF culture supernatant after RB-PDT was significantly higher than in controls (p = 0.02; p = 0.01). No other analyzed mRNA and protein expression differed significantly between the RB-PDT treated and untreated groups. CONCLUSIONS Our study demonstrates that RB-PDT reduces collagen I, collagen V and TGF-β1 mRNA expression, while increasing IL-6 mRNA and protein expression in KC-HCFs. In HCFs, RB-PDT increases TGF-β1 and IL-6 protein level after 24 h.
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Affiliation(s)
- Ning Chai
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany
| | - Tanja Stachon
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany
| | - Tim Berger
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | - Zhen Li
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center, Homburg, Saar, Germany
| | | | - Nóra Szentmáry
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg, Saar, Germany
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary
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Zhu X, Cheng D, Ruan K, Shen M, Ye Y. Causal relationships between type 2 diabetes, glycemic traits and keratoconus. Front Med (Lausanne) 2023; 10:1264061. [PMID: 38020157 PMCID: PMC10658005 DOI: 10.3389/fmed.2023.1264061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 10/24/2023] [Indexed: 12/01/2023] Open
Abstract
Purpose The relationship between diabetes mellitus and keratoconus remains controversial. This study aimed to assess the potential causal relationships among type 2 diabetes, glycemic traits, and the risk of keratoconus. Methods We used a two-sample Mendelian randomization (MR) design based on genome-wide association summary statistics. Fasting glucose, proinsulin levels, adiponectin, hemoglobin A1c (HbA1c) and type 2 diabetes with and without body mass index (BMI) adjustment were used as exposures and keratoconus was used as the outcome. MR analysis was performed using the inverse-variance weighted method, MR-Egger regression method, weighted-mode method, weighted median method and the MR-pleiotropy residual sum and outlier test (PRESSO). Results Results showed that genetically predicted lower fasting glucose were significantly associated with a higher risk of keratoconus [IVW: odds ratio (OR) = 0.382; 95% confidence interval (CI) = 0.261-0.560; p = 8.162 × 10-7]. Genetically predicted lower proinsulin levels were potentially linked to a higher risk of keratoconus (IVW: OR = 0.739; 95% CI = 0.568-0.963; p = 0.025). In addition, genetically predicted type 2 diabetes negatively correlated with keratoconus (IVW: BMI-unadjusted: OR = 0.869; 95% CI = 0.775-0.974, p = 0.016; BMI-adjusted: OR = 0.880, 95% CI = 0.789-0.982, p = 0.022). These associations were further corroborated by the evidence from all sensitivity analyses. Conclusion These findings provide genetic evidence that higher fasting glucose levels are associated with a lower risk of keratoconus. However, further studies are required to confirmed this hypothesis and to understand the mechanisms underlying this putative causative relationship.
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Affiliation(s)
| | | | | | | | - Yufeng Ye
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
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10
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Tran TM, Mittal A, Naik V, Chhadva P, Wade M, Garg S. Prevalence of subclinical keratoconus and impact on adults undergoing routine, uncomplicated age-related cataract extraction. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1269439. [PMID: 38983071 PMCID: PMC11182208 DOI: 10.3389/fopht.2023.1269439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 08/30/2023] [Indexed: 07/11/2024]
Abstract
Aim To determine the prevalence of subclinical keratoconus (SKCN) among individuals undergoing routine, uncomplicated age-related cataract surgery and its impact on visual and refractive outcomes. Patient and Methods At a major academic ophthalmology department in the United States, we reviewed records of patients aged 50 years and older who underwent surgery from January 2011 to June 2022. We excluded patients who had poor-quality or unreliable tomographic data, previous corneal surgery, keratorefractive procedures, and significant vision-limiting ocular pathology. We defined SKCN if an eye had a Belin-Ambrósio enhanced ectasia index (BAD-D) ≥1.7, which was based on the results of a meta-analysis of large studies. In addition to the BAD-D cutoff, the eye had to deviate significantly on at least one of seven additional parameters: 1) posterior elevation at thinnest point, 2) index of vertical asymmetry, 3) index of surface variation, 4) total front higher order aberrations, 5) front vertical coma, 6) front secondary vertical coma, 7) back vertical coma. An individual had SKCN if at least one eye met the tomography-based classification and did not have manifest KCN in either eye. Visual and refractive outcomes data were acquired from patients of one experienced cataract surgeon with cases done from July 2021 to June 2022. Statistical significance was set at p < 0.05. Results Among 5592 eyes from 3828 individuals, the prevalence of SKCN was 24.7% (95% CI, 23.4 - 26.1, 945 individuals), and the prevalence of KCN was 1.9% (95% CI, 1.6 - 2.4, 87 individuals). The prevalence of SKCN did not increase with age and was more prevalent among females and non-white races. Median post-operative month one distance-corrected visual acuity (DCVA) and proportion of eyes with improvement in DCVA were similar between normal and SKCN eyes. The proportion of eyes reaching ±0.5 and ±1.0 diopter within the refractive target were similar between normal and SKCN eyes. Conclusion SKCN is highly prevalent and should be detected but is unlikely to have a significant deleterious effect on outcomes in routine, uncomplicated cataract surgery.
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Affiliation(s)
- Tu M Tran
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, United States
| | - Aman Mittal
- Dean McGee Eye Institute, University of Oklahoma, Oklahoma, OK, United States
| | - Vihar Naik
- School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Priyanka Chhadva
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
| | - Matthew Wade
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
| | - Sumit Garg
- Gavin Herbert Eye Institute, University of California, Irvine, Irvine, CA, United States
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11
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Unni P, Lee HJ. Systemic Associations with Keratoconus. Life (Basel) 2023; 13:1363. [PMID: 37374145 DOI: 10.3390/life13061363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 06/04/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023] Open
Abstract
Keratoconus is a disease of the cornea that results in progressive steepening and thinning of the cornea and subsequent vision loss. It nearly always presents as a bilateral disease, suggesting that there is an underlying abnormality of the corneas that becomes manifest with time. However, the mechanisms underlying the development of keratoconus are largely unknown. Associations reported between keratoconus and systemic diseases are abundant in the literature, and the list of possible associations is very long. We found that atopy, Down syndrome, and various connective tissue diseases were the most frequently cited associations in our broad literature search. Additionally, Diabetes Mellitus has been increasingly studied as a possible protective factor against keratoconus. In this review, we have summarized the evidence for and against these particular systemic conditions and keratoconus and have discussed some of the implications of keratoconus patients having these conditions.
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Affiliation(s)
- Prasida Unni
- Chobanian and Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
| | - Hyunjoo Jean Lee
- Chobanian and Avedisian School of Medicine, Boston University, Boston, MA 02118, USA
- Department of Ophthalmology, Boston Medical Center, Boston, MA 02118, USA
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12
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Li Y, Zheng X, Guo J, Samura M, Ge Y, Zhao S, Li G, Chen X, Shoji T, Ikezoe T, Miyata M, Xu B, Dalman RL. Treatment With Small Molecule Inhibitors of Advanced Glycation End-Products Formation and Advanced Glycation End-Products-Mediated Collagen Cross-Linking Promotes Experimental Aortic Aneurysm Progression in Diabetic Mice. J Am Heart Assoc 2023; 12:e028081. [PMID: 37158066 PMCID: PMC10227285 DOI: 10.1161/jaha.122.028081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 04/14/2023] [Indexed: 05/10/2023]
Abstract
Background Although diabetes attenuates abdominal aortic aneurysms (AAAs), the mechanisms by which diabetes suppresses AAAs remain incompletely understood. Accumulation of advanced glycation end- (AGEs) reduces extracellular matrix (ECM) degradation in diabetes. Because ECM degradation is critical for AAA pathogenesis, we investigated whether AGEs mediate experimental AAA suppression in diabetes by blocking AGE formation or disrupting AGE-ECM cross-linking using small molecule inhibitors. Methods and Results Male C57BL/6J mice were treated with streptozotocin and intra-aortic elastase infusion to induce diabetes and experimental AAAs, respectively. Aminoguanidine (AGE formation inhibitor, 200 mg/kg), alagebrium (AGE-ECM cross-linking disrupter, 20 mg/kg), or vehicle was administered daily to mice from the last day following streptozotocin injection. AAAs were assessed via serial aortic diameter measurements, histopathology, and in vitro medial elastolysis assays. Treatment with aminoguanidine, not alagebrium, diminished AGEs in diabetic AAAs. Treatment with both inhibitors enhanced aortic enlargement in diabetic mice as compared with vehicle treatment. Neither enhanced AAA enlargement in nondiabetic mice. AAA enhancement in diabetic mice by aminoguanidine or alagebrium treatment promoted elastin degradation, smooth muscle cell depletion, mural macrophage accumulation, and neoangiogenesis without affecting matrix metalloproteinases, C-C motif chemokine ligand 2, or serum glucose concentration. Additionally, treatment with both inhibitors reversed suppression of diabetic aortic medial elastolysis by porcine pancreatic elastase in vitro. Conclusions Inhibiting AGE formation or AGE-ECM cross-linking enhances experimental AAAs in diabetes. These findings support the hypothesis that AGEs attenuate experimental AAAs in diabetes. These findings underscore the potential translational value of enhanced ECM cross-linking as an inhibitory strategy for early AAA disease.
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Affiliation(s)
- Yankui Li
- Department of SurgeryStanford University School of MedicineStanfordCAUSA
- Department of Vascular SurgeryTianjin Medical University Second HospitalTianjinChina
| | - Xiaoya Zheng
- Department of SurgeryStanford University School of MedicineStanfordCAUSA
- Department of EndocrinologyThe First Affiliated Hospital of Chongqing Medical UniversityChongqingChina
| | - Jia Guo
- Department of SurgeryStanford University School of MedicineStanfordCAUSA
| | - Makoto Samura
- Department of SurgeryStanford University School of MedicineStanfordCAUSA
| | - Yingbin Ge
- Department of PhysiologyNanjing Medical UniversityNanjingChina
| | - Sihai Zhao
- Department of SurgeryStanford University School of MedicineStanfordCAUSA
| | - Gang Li
- Department of SurgeryStanford University School of MedicineStanfordCAUSA
| | - Xiaofeng Chen
- Department of Radiation OncologyIndiana University School of MedicineIndianapolisINUSA
| | - Takahiro Shoji
- Department of SurgeryStanford University School of MedicineStanfordCAUSA
| | - Toru Ikezoe
- Department of SurgeryStanford University School of MedicineStanfordCAUSA
| | - Masaaki Miyata
- School of Health SciencesKagoshima University Faculty of MedicineKagoshimaJapan
| | - Baohui Xu
- Department of SurgeryStanford University School of MedicineStanfordCAUSA
| | - Ronald L. Dalman
- Department of SurgeryStanford University School of MedicineStanfordCAUSA
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13
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Prasher P, Sharma A, Sharma R, Vig VK, Nirankari VS. Paediatric cornea crosslinking current strategies: A review. ADVANCES IN OPHTHALMOLOGY PRACTICE AND RESEARCH 2023; 3:55-62. [PMID: 37846374 PMCID: PMC10577868 DOI: 10.1016/j.aopr.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 11/13/2022] [Accepted: 11/16/2022] [Indexed: 10/18/2023]
Abstract
Background In the general population, 1 in 2000 people has keratoconus. Indians and other people from Southeast Asia have a higher incidence of keratoconus. Children with keratoconus typically present earlier in life and with a more severe disease. Rubbing the eyes has been identified as a risk factor. Children have a higher incidence and a faster rate of keratoconus progression. Visual rehabilitation in children with keratoconus is challenging. They have a low compliance with contact lens use. Many of these children require penetrating keratoplasty at an early age. Therefore, stopping the progression of keratoconus in children is of paramount importance. Main text Compared to treatment, keratoconus progression prophylaxis is not only preferable, but also easier. Corneal collagen cross-linking has been shown to be safe and effective in stopping its progression in children. The Dresden protocol, which involves central corneal deepithelization (7-9 mm), saturation of the stroma with riboflavin (0.25%), and 30 min UV-A exposure, has proven to be the most successful. Two significant disadvantages of the typical Dresden regimen are the prolonged operating time and the significant post-operative pain. Accelerated-CXL (9 mW/cm2 x 10 min) has been studied to reduce operative time and has been shown to be equally effective in some studies. Compared to accelerated CXL or traditional CXL, epi-off procedures, transepithelial treatment without the need for de-epithelialization and without postoperative discomfort, have been shown to be safer but less effective. Corneal crosslinking should only be performed after treating children with active vernal keratoconjunctivitis. Corneal opacity, chronic corneal edema, sterile infiltrates, and microbial keratitis have been reported after cross-linking of corneal collagen. Conclusions The "Dresden protocol", also known as the conventional corneal cross-linking approach, should be used to halt the progression of keratoconus in young patients. However, if the procedure needs to be completed more rapidly, accelerated corneal crosslinking may be considered. Transepithelial corneal cross-linking has been proven to be less effective at stabilizing keratoconus, although being more safer.
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Affiliation(s)
- Pawan Prasher
- Department of Ophthalmology, Sri Guru Ram Das Institute of Medical Sciences and Research, Amritsar, Punjab, India
| | - Ashok Sharma
- Cornea Centre, SCO 2463 - 2464, Sector 22 C, 160022, Chandigarh, India
| | - Rajan Sharma
- Cornea Centre, SCO 2463 - 2464, Sector 22 C, 160022, Chandigarh, India
| | - Vipan K. Vig
- Amritsar Eye Hospital, GNDU Shopping Complex, Amritsar, Punjab, India
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14
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Yang Q, Wang S, He Y, Zhang Y. The research progress on the molecular mechanism of corneal cross-linking in keratoconus treatment. Cont Lens Anterior Eye 2023; 46:101795. [PMID: 36549953 DOI: 10.1016/j.clae.2022.101795] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 12/05/2022] [Accepted: 12/08/2022] [Indexed: 12/24/2022]
Abstract
Keratoconus (KC) is a corneal anomaly that is manifested in a limited cone-like bulge with corneal thinning. Many molecules in the cornea change during the development of KC, including various components of the extracellular matrix, cytokines, cell connection, and cell adhesion-related proteins. Several treatment options are available, with corneal cross-linking (CXL) being the treatment of choice for early KC. However, postoperative complications have been reported in some CXL patients, mainly caused by corneal epithelial resection. Despite the fact that some novel approaches have helped to reduce some of the initial post-operative issues, their effectiveness seems to be inferior to that of the original CXL. To keep effectiveness while avoiding these negative effects, it is necessary to study the mechanism of CXL in KC treatment at the molecular level. This article provides a review of the molecular mechanism of CXL in the treatment of KC from four aspects: enzyme activity, signal transduction pathway, corneal-related proteins, and other KC-related molecules, further confirming the feasibility of CXL treatment of KC, providing new ideas for improving CXL.
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Affiliation(s)
- Qingyu Yang
- Department of Ophthalmology, 2nd Hospital of Jilin University, Changchun 130041, China.
| | - Shurong Wang
- Department of Ophthalmology, 2nd Hospital of Jilin University, Changchun 130041, China.
| | - Yuxi He
- Department of Ophthalmology, 2nd Hospital of Jilin University, Changchun 130041, China
| | - Yan Zhang
- Department of Ophthalmology, 2nd Hospital of Jilin University, Changchun 130041, China.
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15
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Urbánek P, Šuly P, Ševčík J, Hanulíková B, Kuřitka I, Šopík T, Stodůlka P. Controlled Drug Delivery Device for Cornea Treatment and Novel Method for Its Testing. Pharmaceuticals (Basel) 2023; 16:ph16040505. [PMID: 37111260 PMCID: PMC10143253 DOI: 10.3390/ph16040505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 03/23/2023] [Accepted: 03/24/2023] [Indexed: 03/30/2023] Open
Abstract
A new solution for local anesthetic and antibiotic delivery after eye surgery is presented. A contact lens-shaped collagen drug carrier was created and loaded by Levofloxacin and Tetracaine with a riboflavin crosslinked surface layer, thus impeding diffusion. The crosslinking was confirmed by Raman spectroscopy, whereas the drug release was investigated using UV-Vis spectrometry. Due to the surface barrier, the drug gradually releases into the corneal tissue. To test the function of the carrier, a 3D printed device and a new test method for a controlled drug release, which mimics the geometry and physiological lacrimation rate of the human eye, were developed. The experimental setup with simple geometry revealed that the prepared drug delivery device can provide the prolonged release profile of the pseudo-first-order for up to 72 h. The efficiency of the drug delivery was further demonstrated using a dead porcine cornea as a drug recipient, without the need to use live animals for testing. Our drug delivery system significantly surpasses the efficiency of antibiotic and anesthetic eyedrops that would have to be applied approximately 30 times per hour to achieve the same dose as that delivered continuously by our device.
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Affiliation(s)
- Pavel Urbánek
- Centre of Polymer Systems, Tomas Bata University in Zlín, trida Tomase Bati 5678, 76001 Zlin, Czech Republic
- Correspondence:
| | - Pavol Šuly
- Centre of Polymer Systems, Tomas Bata University in Zlín, trida Tomase Bati 5678, 76001 Zlin, Czech Republic
| | - Jakub Ševčík
- Centre of Polymer Systems, Tomas Bata University in Zlín, trida Tomase Bati 5678, 76001 Zlin, Czech Republic
| | - Barbora Hanulíková
- Centre of Polymer Systems, Tomas Bata University in Zlín, trida Tomase Bati 5678, 76001 Zlin, Czech Republic
| | - Ivo Kuřitka
- Centre of Polymer Systems, Tomas Bata University in Zlín, trida Tomase Bati 5678, 76001 Zlin, Czech Republic
| | - Tomáš Šopík
- Centre of Polymer Systems, Tomas Bata University in Zlín, trida Tomase Bati 5678, 76001 Zlin, Czech Republic
| | - Pavel Stodůlka
- Gemini Eye Clinic, U Gemini 360, 76001 Zlin, Czech Republic
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16
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Biomechanics of keratoconus: Two numerical studies. PLoS One 2023; 18:e0278455. [PMID: 36730305 PMCID: PMC9894483 DOI: 10.1371/journal.pone.0278455] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 11/16/2022] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND The steep cornea in keratoconus can greatly impair eyesight. The etiology of keratoconus remains unclear but early injury that weakens the corneal stromal architecture has been implicated. To explore keratoconus mechanics, we conducted two numerical simulation studies. METHODS A finite-element model describing the five corneal layers and the heterogeneous mechanical behaviors of the ground substance and lamellar collagen-fiber architecture in the anterior and posterior stroma was developed using the Holzapfel-Gasser-Ogden constitutive model. The geometry was from a healthy subject. Its stroma was divided into anterior, middle, and posterior layers to assess the effect of changing regional mechanical parameters on corneal displacement and maximum principal stress under intraocular pressure. Specifically, the effect of softening an inferocentral corneal button, the collagen-based tissues throughout the whole cornea, or specific stromal layers in the button was examined. The effect of simply disorganizing the orthogonally-oriented posterior stromal fibers in the button was also assessed. The healthy cornea was also subjected to eye rubbing-like loading to identify the corneal layer(s) that experienced the most tensional stress. RESULTS Conical deformation and corneal thinning emerged when the corneal button or the mid-posterior stroma of the button underwent gradual softening or when the collagen fibers in the mid-posterior stroma of the button were dispersed. Softening the anterior layers of the button or the whole cornea did not evoke conical deformation. Button softening greatly increased and disrupted the stress on Bowman's membrane while mid-posterior stromal softening increased stress in the anterior layers. Eye rubbing profoundly stressed the deep posterior stroma while other layers were negligibly affected. DISCUSSION These observations suggest that keratoconus could be initiated, at least partly, by mechanical instability/damage in the mid-posterior stroma that then imposes stress on the anterior layers. This may explain why subclinical keratoconus is marked by posterior but not anterior elevation on videokeratoscopy.
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17
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Cheng Y, Ren T, Wang N. Biomechanical homeostasis in ocular diseases: A mini-review. Front Public Health 2023; 11:1106728. [PMID: 36733902 PMCID: PMC9886686 DOI: 10.3389/fpubh.2023.1106728] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 01/02/2023] [Indexed: 01/18/2023] Open
Abstract
Diabetes mellitus-induced hyperglycemia is responsible for multiple pathological ocular alternations from vasculopathy to biomechanical dyshomeostasis. Biomechanical homeostasis is crucial to maintain the normal physiological condition of the eyes. Biomechanical features vary in eye tissues regarding different anatomical positions, tissue components, and cellular functions. The disturbance in biomechanical homeostasis may result in different ocular diseases. In this review, we provide a preliminary sketch of the latest evidence on the mechano-environment of the eyeball and its possible influencing factors, thereby underscoring the relationship between the dyshomeostasis of ocular biomechanics and common eye diseases (e.g., diabetic retinopathy, keratoconus, glaucoma, spaceflight-associated neuro-ocular syndrome, retinal vein occlusion and myopia, etc.). Together with the reported evidence, we further discuss and postulate the potential role of biomechanical homeostasis in ophthalmic pathology. Some latest strategies to investigate the biomechanical properties in ocular diseases help unveil the pathological changes at multiple scales, offering references for making new diagnostic and treatment strategies targeting mechanobiology.
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Affiliation(s)
- Ying Cheng
- Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Tianmin Ren
- Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Ningli Wang
- Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China,Collaborative Innovation Center for Brain Disorders, Beijing Institute of Brain Disorders, Capital Medical University, Beijing, China,Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing, China,*Correspondence: Ningli Wang ✉
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18
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Araújo ERD, Xavier-Santos JB, da Silva VC, de Lima JBF, Schlamb J, Fernandes-Pedrosa MDF, da Silva Júnior AA, de Araújo Júnior RF, Rathinasabapathy T, Moncada M, Esposito D, Guerra GCB, Zucolotto SM. Gel formulated with Bryophyllum pinnatum leaf extract promotes skin wound healing in vivo by increasing VEGF expression: A novel potential active ingredient for pharmaceuticals. Front Pharmacol 2023; 13:1104705. [PMID: 36712663 PMCID: PMC9877235 DOI: 10.3389/fphar.2022.1104705] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 12/23/2022] [Indexed: 01/15/2023] Open
Abstract
Bryophyllum pinnatum (Crassulaceae) is used in traditional medicine for treating skin wounds. In our previous study, a topical gel containing B. pinnatum aqueous leaf extract showed a preclinical anti-inflammatory effect in in vivo acute edema models. In continuation, the present study aims to evaluate the phytochemical content and the stability of a formulation in gel containing B. pinnatum aqueous leaf extract and its healing properties and mechanism of action through an experimental model of induction of skin wounds in rats and in vitro assays. The animals were treated topically for 7 or 14 days with a formulation in gel containing extract at 5% or a placebo or Fibrinase® in cream. In addition, to establish some quality control parameters, the total phenolic content (TPC), total flavonoid content (TFC), and a study focusing on the phytochemical and biological stability of a gel for 30 days at two different conditions (room temperature and 40°C/75% RH) were performed. Gel formulation containing extract showed a TPC and TFC of 2.77 ± 0.06 mg of gallic acid/g and 1.58 ± 0.03 mg of quercetin/g, respectively. Regarding the stability study, the formulation in gel showed no significant change in the following parameters: pH, water activity, chromatographic profile, and the content of the major compound identified in the extract. The gel formulation containing extract stimulated skin wound healing while reducing the wound area, as well as decreasing the inflammatory infiltrate, reducing the levels of IL-1β and TNF-α, and stimulating angiogenesis with increased expression of VEGF, an effect similar to Fibrinase. In conclusion, the gel formulation containing extract exhibited relevant skin wound healing properties and, therefore, has the potential to be applied as a novel active ingredient for developing wound healing pharmaceuticals.
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Affiliation(s)
- Edilane Rodrigues Dantas Araújo
- Postgraduate Program in Health Science, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil,Department of Pharmacy, Research Group on Bioactive Natural Products, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Jacinthia Beatriz Xavier-Santos
- Postgraduate Program in Pharmaceutical Science, Federal University of Rio Grande do Norte, Natal, Brazil,Biotechnology and Technology Laboratory, Department of Pharmacy, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Valéria Costa da Silva
- Department of Pharmacy, Research Group on Bioactive Natural Products, Federal University of Rio Grande do Norte, Natal, Brazil,Postgraduate Program in Drug Development and Technological Innovation, Federal University of Rio Grande do Norte, Natal, Brazil
| | | | - Jade Schlamb
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, United States
| | - Matheus de Freitas Fernandes-Pedrosa
- Postgraduate Program in Pharmaceutical Science, Federal University of Rio Grande do Norte, Natal, Brazil,Biotechnology and Technology Laboratory, Department of Pharmacy, Federal University of Rio Grande do Norte, Natal, Brazil,Postgraduate Program in Drug Development and Technological Innovation, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Arnóbio Antônio da Silva Júnior
- Postgraduate Program in Health Science, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil,Postgraduate Program in Pharmaceutical Science, Federal University of Rio Grande do Norte, Natal, Brazil,Biotechnology and Technology Laboratory, Department of Pharmacy, Federal University of Rio Grande do Norte, Natal, Brazil,Postgraduate Program in Drug Development and Technological Innovation, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Raimundo Fernandes de Araújo Júnior
- Postgraduate Program in Health Science, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil,Cancer and Inflammation Research Laboratory, Morphology Department, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | | | - Marvin Moncada
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, United States,Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC, United States
| | - Debora Esposito
- Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, United States,Department of Animal Science, NC State University, Raleigh, NC, United States
| | - Gerlane Coelho Bernardo Guerra
- Postgraduate Program in Pharmaceutical Science, Federal University of Rio Grande do Norte, Natal, Brazil,Department of Biophysics and Pharmacology, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Silvana Maria Zucolotto
- Postgraduate Program in Health Science, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil,Department of Pharmacy, Research Group on Bioactive Natural Products, Federal University of Rio Grande do Norte, Natal, Brazil,Postgraduate Program in Pharmaceutical Science, Federal University of Rio Grande do Norte, Natal, Brazil,Postgraduate Program in Drug Development and Technological Innovation, Federal University of Rio Grande do Norte, Natal, Brazil,Plants for Human Health Institute, North Carolina State University, Kannapolis, NC, United States,*Correspondence: Silvana Maria Zucolotto,
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19
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Evaluation of Eyelid, Angle, and Anterior Segment Parameters Using Scheimpflug Camera and Topography System in Obstructive Sleep Apnea Syndrome. BEYOGLU EYE JOURNAL 2023; 8:5-13. [PMID: 36911217 PMCID: PMC9993417 DOI: 10.14744/bej.2022.94899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 01/03/2023] [Accepted: 01/06/2023] [Indexed: 02/23/2023]
Abstract
Objectives The purpose of the study was to investigate the eyelid hyperlaxity, anterior segment, and corneal topographic parameters in patients with obstructive sleep apnea syndrome (OSAS) using Scheimpflug camera and topography system. Methods In this prospective and cross-sectional clinical study, 32 eyes of 32 patients with OSAS and thirty-two eyes of 32 healthy subjects were evaluated. The participants with OSAS were selected from those with an apnea-hypopnea index ≥ 15. The minimum corneal thickness (ThkMin), apical corneal thickness (ACT), central corneal thickness (CCT), pupillary diameter (PD), aqueous depth (AD), aqueous volume (AV), anterior chamber angle (ACA), horizontal anterior chamber diameter (HACD), corneal volume (CV), simulated K readings (sim-K), front and back corneal keratometric values at 3 mm, RMS/A values, highest point of ectasia on the anterior and posterior corneal surface (KVf, KVb), symmetry indices and keratoconus measurements were taken by combined Scheimpflug-Placido corneal topography and compared with healthy subjects. Upper eyelid hyperlaxity (UEH) and floppy eyelid syndrome were also evaluated. Results There were no statistically significant difference between groups in terms of age, gender, PD, ACT, CV, HACD, simK readings, front and back keratometric values, RMS/A-KVf and KVb values, symmetry indices, and keratoconus measurements (p>0.05). ThkMin, CCT, AD, AV, and ACA values were significantly higher in OSAS group compared to the control (p<0.05). UEH was detected in two cases in the control group (6.3%) and in 13 cases in the OSAS group (40.6%) and the difference was significant (p<0.001). Conclusion The anterior chamber depth, ACA, AV, CCT, and UEH increase in OSAS. These ocular morphological changes occurring in OSAS may explain why these patients prones to normotensive glaucoma.
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Vaez M, Asgari M, Hirvonen L, Bakir G, Khattignavong E, Ezzo M, Aguayo S, Schuh CM, Gough K, Bozec L. Modulation of the biophysical and biochemical properties of collagen by glycation for tissue engineering applications. Acta Biomater 2023; 155:182-198. [PMID: 36435437 DOI: 10.1016/j.actbio.2022.11.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 11/08/2022] [Accepted: 11/16/2022] [Indexed: 11/25/2022]
Abstract
The structural and functional properties of collagen are modulated by the presence of intramolecular and intermolecular crosslinks. Advanced Glycation End-products (AGEs) can produce intermolecular crosslinks by bonding the free amino groups of neighbouring proteins. In this research, the following hypothesis is explored: The accumulation of AGEs in collagen decreases its proteolytic degradation rates while increasing its stiffness. Fluorescence Lifetime Imaging (FLIM) and Fourier-transform infrared spectroscopy (FTIR) detect biochemical changes in collagen scaffolds during the glycation process. The accumulation of AGEs increases exponentially in the collagen scaffolds as a function of Methylglyoxal (MGO) concentration by performing autofluorescence measurement and competitive ELISA. Glycated scaffolds absorb water at a much higher rate confirming the direct affinity between AGEs and interstitial water within collagen fibrils. In addition, the topology of collagen fibrils as observed by Atomic Force Microscopy (AFM) is a lot more defined following glycation. The elastic modulus of collagen fibrils decreases as a function of glycation, whereas the elastic modulus of collagen scaffolds increases. Finally, the enzymatic degradation of collagen by bacterial collagenase shows a sigmoidal pattern with a much slower degradation rate in the glycated scaffolds. This study identifies unique variations in the properties of collagen following the accumulation of AGEs. STATEMENT OF SIGNIFICANCE: In humans, Advanced Glycation End-products (AGEs) are naturally produced as a result of aging process. There is an evident lack of knowledge in the basic science literature explaining the biomechanical impact of AGE-mediated crosslinks on the functional and structural properties of collagen at both the nanoscale (single fibrils) and mesoscale (bundles of fibrils). This research, demonstrates how it is possible to harness this natural phenomenon in vitro to enhance the properties of engineered collagen fibrils and scaffolds. This study identifies unique variations in the properties of collagen at nanoscale and mesoscale following accumulation of AGEs. In their approach, they investigate the unique properties conferred to collagen, namely enhanced water sorption, differential elastic modulus, and finally sigmoidal proteolytic degradation behavior.
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Affiliation(s)
- Mina Vaez
- Faculty of Dentistry, University of Toronto, Toronto, Canada.
| | - Meisam Asgari
- Department of Mechanical Engineering, McGill University, Montreal, Canada
| | - Liisa Hirvonen
- Centre for Microscopy, Characterisation & Analysis, University of Western Australia, Perth, Australia
| | - Gorkem Bakir
- Department of Chemistry, University of Manitoba, Winnipeg, Canada
| | | | - Maya Ezzo
- Faculty of Dentistry, University of Toronto, Toronto, Canada
| | - Sebastian Aguayo
- Dentistry School, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile; Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Christina M Schuh
- Centro de Medicina Regenerativa, Facultad de Medicina Clínica Alemana-Universidad del Desarrollo, Santiago, Chile
| | - Kathleen Gough
- Department of Chemistry, University of Manitoba, Winnipeg, Canada
| | - Laurent Bozec
- Faculty of Dentistry, University of Toronto, Toronto, Canada
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21
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Role of Collagen in Vascular Calcification. J Cardiovasc Pharmacol 2022; 80:769-778. [PMID: 35998017 DOI: 10.1097/fjc.0000000000001359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 08/03/2022] [Indexed: 12/13/2022]
Abstract
ABSTRACT Vascular calcification is a pathological process characterized by ectopic calcification of the vascular wall. Medial calcifications are most often associated with kidney disease, diabetes, hypertension, and advanced age. Intimal calcifications are associated with atherosclerosis. Collagen can regulate mineralization by binding to apatite minerals and promoting their deposition, binding to collagen receptors to initiate signal transduction, and inducing cell transdifferentiation. In the process of vascular calcification, type I collagen is not only the scaffold for mineral deposition but also a signal entity, guiding the distribution, aggregation, and nucleation of vesicles and promoting the transformation of vascular smooth muscle cells into osteochondral-like cells. In recent years, collagen has been shown to affect vascular calcification through collagen disc-domain receptors, matrix vesicles, and transdifferentiation of vascular smooth muscle cells.
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22
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Potekaev NN, Borzykh OB, Shnayder NA, Petrova MM, Karpova EI, Nasyrova RF. Collagen synthesis in the skin: genetic and epigenetic aspects. BULLETIN OF SIBERIAN MEDICINE 2022. [DOI: 10.20538/1682-0363-2022-3-217-226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
One of the most important functions of the skin, mechanical, is provided by collagen fibers and their interaction with other elements of the extracellular matrix. Synthesis of collagen fibers is a complex multistep process. At each stage, disturbances may occur, leading, as a result, to a decrease in the mechanical properties of the connective tissue. In clinical practice, disorders of collagen synthesis are manifested through increased skin laxity and looseness and premature aging. In addition to the clinical presentation, it is important for the cosmetologist and dermatologist to understand the etiology and pathogenesis of collagenopathies. The present review summarizes and systematizes available information about the role of genetic and epigenetic factors in the synthesis of collagen fibers in the skin. Understanding the etiology of collagen synthesis disorders can allow doctors to prescribe pathogenetically grounded treatment with the most effective results and minimize adverse reactions.
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Affiliation(s)
- N. N. Potekaev
- Pirogov Russian National Research Medical University; Moscow Research and Practical Center for Dermatology and Cosmetology, Department of Healthcare
| | - O. B. Borzykh
- V.F. Voino-Yasenetsky Krasnoyarsk State Medical University
| | - N. A. Shnayder
- V.F. Voino-Yasenetsky Krasnoyarsk State Medical University; Bekhterev Psychoneurological Research Institute
| | - M. M. Petrova
- V.F. Voino-Yasenetsky Krasnoyarsk State Medical University
| | - E. I. Karpova
- Pirogov Russian National Research Medical University
| | - R. F. Nasyrova
- Bekhterev Psychoneurological Research Institute; Kazan Federal University
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Akoto T, Li JJ, Estes AJ, Karamichos D, Liu Y. The Underlying Relationship between Keratoconus and Down Syndrome. Int J Mol Sci 2022; 23:ijms231810796. [PMID: 36142709 PMCID: PMC9503764 DOI: 10.3390/ijms231810796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 11/16/2022] Open
Abstract
Keratoconus (KC) is one of the most significant corneal disorders worldwide, characterized by the progressive thinning and cone-shaped protrusion of the cornea, which can lead to severe visual impairment. The prevalence of KC varies greatly by ethnic groups and geographic regions and has been observed to be higher in recent years. Although studies reveal a possible link between KC and genetics, hormonal disturbances, environmental factors, and specific comorbidities such as Down Syndrome (DS), the exact cause of KC remains unknown. The incidence of KC ranges from 0% to 71% in DS patients, implying that as the worldwide population of DS patients grows, the number of KC patients may continue to rise significantly. As a result, this review aims to shed more light on the underlying relationship between KC and DS by examining the genetics relating to the cornea, central corneal thickness (CCT), and mechanical forces on the cornea, such as vigorous eye rubbing. Furthermore, this review discusses KC diagnostic and treatment strategies that may help detect KC in DS patients, as well as the available DS mouse models that could be used in modeling KC in DS patients. In summary, this review will provide improved clinical knowledge of KC in DS patients and promote additional KC-related research in these patients to enhance their eyesight and provide suitable treatment targets.
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Affiliation(s)
- Theresa Akoto
- Department of Cellular Biology & Anatomy, Augusta University, Augusta, GA 30912, USA
| | - Jiemin J. Li
- Department of Cellular Biology & Anatomy, 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
| | - 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, 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
- Correspondence: ; Tel.: +1-706-721-2015
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Clua‐Ferré L, De Chiara F, Rodríguez‐Comas J, Comelles J, Martinez E, Godeau AL, García‐Alamán A, Gasa R, Ramón‐Azcón J. Collagen-Tannic Acid Spheroids for β-Cell Encapsulation Fabricated Using a 3D Bioprinter. ADVANCED MATERIALS TECHNOLOGIES 2022; 7:2101696. [PMID: 37182094 PMCID: PMC10170414 DOI: 10.1002/admt.202101696] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/18/2022] [Indexed: 05/16/2023]
Abstract
Type 1 Diabetes results from autoimmune response elicited against β-cell antigens. Nowadays, insulin injections remain the leading therapeutic option. However, injection treatment fails to emulate the highly dynamic insulin release that β-cells provide. 3D cell-laden microspheres have been proposed during the last years as a major platform for bioengineering insulin-secreting constructs for tissue graft implantation and a model for in vitro drug screening platforms. Current microsphere fabrication technologies have several drawbacks: the need for an oil phase containing surfactants, diameter inconsistency of the microspheres, and high time-consuming processes. These technologies have widely used alginate for its rapid gelation, high processability, and low cost. However, its low biocompatible properties do not provide effective cell attachment. This study proposes a high-throughput methodology using a 3D bioprinter that employs an ECM-like microenvironment for effective cell-laden microsphere production to overcome these limitations. Crosslinking the resulting microspheres with tannic acid prevents collagenase degradation and enhances spherical structural consistency while allowing the diffusion of nutrients and oxygen. The approach allows customization of microsphere diameter with extremely low variability. In conclusion, a novel bio-printing procedure is developed to fabricate large amounts of reproducible microspheres capable of secreting insulin in response to extracellular glucose stimuli.
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Affiliation(s)
- Laura Clua‐Ferré
- Institute for Bioengineering of Catalonia (IBEC)The Barcelona Institute of Science and Technology (BIST)Baldiri I Reixac, 10–12Barcelona08028Spain
| | - Francesco De Chiara
- Institute for Bioengineering of Catalonia (IBEC)The Barcelona Institute of Science and Technology (BIST)Baldiri I Reixac, 10–12Barcelona08028Spain
| | - Júlia Rodríguez‐Comas
- Institute for Bioengineering of Catalonia (IBEC)The Barcelona Institute of Science and Technology (BIST)Baldiri I Reixac, 10–12Barcelona08028Spain
| | - Jordi Comelles
- Institute for Bioengineering of Catalonia (IBEC)The Barcelona Institute of Science and Technology (BIST)Baldiri I Reixac, 10–12Barcelona08028Spain
- Department of Electronics and Biomedical EngineeringUniversity of Barcelona (UB)c/Martí i Franquès 1–11BarcelonaE08028Spain
| | - Elena Martinez
- Institute for Bioengineering of Catalonia (IBEC)The Barcelona Institute of Science and Technology (BIST)Baldiri I Reixac, 10–12Barcelona08028Spain
- Department of Electronics and Biomedical EngineeringUniversity of Barcelona (UB)c/Martí i Franquès 1–11BarcelonaE08028Spain
- Centro de Investigación Biomédica en Red (CIBER)Av. Monforte de Lemos 3–5, Pabellón 11, Planta 0MadridE28029Spain
| | - Amelie Luise Godeau
- Institute for Bioengineering of Catalonia (IBEC)The Barcelona Institute of Science and Technology (BIST)Baldiri I Reixac, 10–12Barcelona08028Spain
| | - Ainhoa García‐Alamán
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM)Madrid28029Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)Barcelona08036Spain
| | - Rosa Gasa
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM)Madrid28029Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)Barcelona08036Spain
| | - Javier Ramón‐Azcón
- Institute for Bioengineering of Catalonia (IBEC)The Barcelona Institute of Science and Technology (BIST)Baldiri I Reixac, 10–12Barcelona08028Spain
- Institució Catalana de Reserca I Estudis Avançats (ICREA)Passeig de Lluís Companys, 23BarcelonaE08010Spain
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25
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Gouldin AG, Brown ME, Puetzer JL. An inducible model for unraveling the effects of advanced glycation end-product accumulation in aging connective tissues. Connect Tissue Res 2022; 63:406-424. [PMID: 34706612 DOI: 10.1080/03008207.2021.1991333] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE In connective tissues there is a clear link between increasing age and degeneration. Advanced glycation end-products (AGEs) are believed to play a central role. AGEs are sugar-induced non-enzymatic crosslinks which accumulate in collagen with age and diabetes, altering tissue mechanics and cellular function. Despite ample correlative evidence linking collagen glycation to tissue degeneration, little is known how AGEs impact cell-matrix interactions, limiting therapeutic options. One reason for this limited understanding is that AGEs are typically induced using high concentrations of ribose which decrease cell viability, making it impossible to investigate cell-matrix interactions. The objective of this study was to develop a system to trigger AGE accumulation while maintaining cell viability. MATERIALS AND METHODS Using cell-seeded high density collagen gels, we investigated the effect of two systems for AGE induction, ribose at low concentrations (30, 100, and 200 mM) over 15 days of culture and riboflavin (0.25 and 0.75 mM) induced with blue light for 40 seconds (riboflavin-465 nm). RESULTS We found ribose and riboflavin-465 nm treatment produces fluorescent AGE quantities which match and/or exceed human fluorescent AGE levels for various tissues, ages, and diseases, without affecting cell viability or metabolism. Interestingly, a 40 second treatment of riboflavin-465 nm produced similar levels of fluorescent AGEs as 3 days of 100 mM ribose treatment. CONCLUSIONS Riboflavin-465 nm is a promising method to trigger AGEs on demand in vivo or in vitro without impacting cell viability and offers potential for unraveling the mechanism of AGEs in age and diabetes related tissue damage.
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Affiliation(s)
- Austin G Gouldin
- Departments of Biomedical Engineering; Orthopaedic Surgery, Virginia Commonwealth University, Richmond, Virginia, United States
| | - M Ethan Brown
- Departments of Biomedical Engineering; Orthopaedic Surgery, Virginia Commonwealth University, Richmond, Virginia, United States
| | - Jennifer L Puetzer
- Departments of Biomedical Engineering; Orthopaedic Surgery, Virginia Commonwealth University, Richmond, Virginia, United States
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26
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Corneal stromal repair and regeneration. Prog Retin Eye Res 2022; 91:101090. [DOI: 10.1016/j.preteyeres.2022.101090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 01/02/2023]
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Advanced Glycation End-Products (AGEs): Formation, Chemistry, Classification, Receptors, and Diseases Related to AGEs. Cells 2022; 11:cells11081312. [PMID: 35455991 PMCID: PMC9029922 DOI: 10.3390/cells11081312] [Citation(s) in RCA: 165] [Impact Index Per Article: 82.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/08/2022] [Accepted: 04/11/2022] [Indexed: 01/27/2023] Open
Abstract
Advanced glycation end-products (AGEs) constitute a non-homogenous, chemically diverse group of compounds formed either exogeneously or endogeneously on the course of various pathways in the human body. In general, they are formed non-enzymatically by condensation between carbonyl groups of reducing sugars and free amine groups of nucleic acids, proteins, or lipids, followed by further rearrangements yielding stable, irreversible end-products. In the last decades, AGEs have aroused the interest of the scientific community due to the increasing evidence of their involvement in many pathophysiological processes and diseases, such as diabetes, cancer, cardiovascular, neurodegenerative diseases, and even infection with the SARS-CoV-2 virus. They are recognized by several cellular receptors and trigger many signaling pathways related to inflammation and oxidative stress. Despite many experimental research outcomes published recently, the complexity of their engagement in human physiology and pathophysiological states requires further elucidation. This review focuses on the receptors of AGEs, especially on the structural aspects of receptor-ligand interaction, and the diseases in which AGEs are involved. It also aims to present AGE classification in subgroups and to describe the basic processes leading to both exogeneous and endogeneous AGE formation.
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Danielewska ME, Kostyszak MA, Sareło P, Gąsior-Głogowska M, Niemczyk M, Prządka P, Antończyk A, Kiełbowicz Z, Iskander DR. Indirectly assessing changes in corneal properties with OCT speckle after crosslinking in porcine eyes. Exp Eye Res 2022; 219:109051. [PMID: 35367416 DOI: 10.1016/j.exer.2022.109051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 02/25/2022] [Accepted: 03/22/2022] [Indexed: 11/04/2022]
Abstract
The aim of this study was to assess the effect of the standard crosslinking (CXL) procedure on corneal properties and subsequent changes in collagen bonds formation using optical coherence tomography (OCT) corneal speckle statistics and vibrational spectroscopy. Porcine eyes with intact corneal epithelium were randomly selected to one of the four study groups: (1) untreated eyes moistened with phosphate-buffered saline (PBS); (2) eyes after the epithelial debridement and riboflavin application; (3) eyes after CXL procedure according to the Dresden protocol; and (4) eyes after corneal epithelial debridement, regularly moistened with PBS. Before and after this selection, each eyeball was subjected to the constant intraocular pressure of 20 mmHg. Then, ocular biometry was performed and the central cornea was imaged using spectral-domain OCT. Following this, a nonparametric approach to speckle modeling (the Contrast Ratio (CR)) was utilized within the region of interest for each B-scan covering the central corneal stroma. To verify whether the CXL performed ex-vivo results in formation of new bonds in the cornea, Fourier Transform Infrared Attenuated Total Reflectance (ATR-FTIR) spectra of dried corneas, dissected from examined eyeballs, were collected and analyzed. Corneal epithelium removal alone or with the riboflavin application leads to a statistically significant decrease in the CR median value (the Wilcoxon signed-rank test, p < 0.05). However, the most pronounced change in CR median value, which decreases with the increased number of scatterers, was shown after the complete CXL procedure including riboflavin soaking and UVA irradiation (the Wilcoxon signed-rank test, p = 0.004). Analysis of ATR-FTIR spectra revealed influence of UVA irradiation on collagen matrix. The study has shown the increased dehydration accompanied by almost no alteration of collagen native triple-helical structure. Significant changes have been observed for bands related to collagen crosslinks. Specifically, the predominant changes occurred in the sugar region from 1150 to 975 cm-1, as well as in the absorbance of carbonyl groups. Furthermore, the ratio of two Amide I components at approximately 1660 cm-1 and 1675 cm-1 decreased after UVA irradiation. Together, these results provided the evidence for the creation of new corneal crosslinks. In conclusion, this study clearly indicates that the UVA exposure causes the substantial difference in optical scattering occurring in corneal stroma as a result of the induced biochemical changes at the molecular level in this tissue assessed with ATR-FTIR. The proposed speckle-based methodology brings a new insight into the development of OCT technology useful in an indirect assessment of some collagen changes.
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Affiliation(s)
- Monika E Danielewska
- Wrocław University of Science and Technology, Department of Biomedical Engineering, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
| | - Małgorzata A Kostyszak
- Wrocław University of Science and Technology, Department of Biomedical Engineering, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
| | - Przemysław Sareło
- Wrocław University of Science and Technology, Department of Biomedical Engineering, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
| | - Marlena Gąsior-Głogowska
- Wrocław University of Science and Technology, Department of Biomedical Engineering, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
| | - Marcela Niemczyk
- Wrocław University of Science and Technology, Department of Biomedical Engineering, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
| | - Przemysław Prządka
- Wrocław University of Environmental and Life Sciences, Department and Clinic of Surgery, Faculty of Veterinary Medicine, Pl. Grunwaldzki 51, 50-366, Wrocław, Poland.
| | - Agnieszka Antończyk
- Wrocław University of Environmental and Life Sciences, Department and Clinic of Surgery, Faculty of Veterinary Medicine, Pl. Grunwaldzki 51, 50-366, Wrocław, Poland.
| | - Zdzisław Kiełbowicz
- Wrocław University of Environmental and Life Sciences, Department and Clinic of Surgery, Faculty of Veterinary Medicine, Pl. Grunwaldzki 51, 50-366, Wrocław, Poland.
| | - D Robert Iskander
- Wrocław University of Science and Technology, Department of Biomedical Engineering, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
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Lasagni Vitar RM, Bonelli F, Rama P, Ferrari G. Nutritional and Metabolic Imbalance in Keratoconus. Nutrients 2022; 14:nu14040913. [PMID: 35215563 PMCID: PMC8876314 DOI: 10.3390/nu14040913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/18/2022] [Indexed: 12/31/2022] Open
Abstract
Keratoconus (KC) is a progressive corneal degeneration characterized by structural changes consisting of progressive thinning and steepening of the cornea. These alterations result in biomechanical weakening and, clinically, in vision loss. While the etiology of KC has been the object of study for over a century, no single agent has been found. Recent reviews suggest that KC is a multifactorial disease that is associated with a wide variety of genetic and environmental factors. While KC is typically considered a disease of the cornea, associations with systemic conditions have been well described over the years. In particular, nutritional and metabolic imbalance, such as the redox status, hormones, metabolites, and micronutrients (vitamins and metal ions), can deeply influence KC initiation and progression. In this paper, we comprehensively review the different nutritional (vitamins and minerals) and metabolic (hormones and metabolites) factors that are altered in KC, discussing their possible implication in the pathophysiology of the disease.
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Affiliation(s)
| | | | | | - Giulio Ferrari
- Correspondence: ; Tel.: +39-02-26436186; Fax: +39-02-26436164
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30
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Shah SG, Shetty R, Ghosh A, Shah GY. Corneal scarring following collagen cross-linking: evidence of increased lysyl oxidase activity. Eur J Ophthalmol 2022; 33:NP23-NP26. [PMID: 35130082 DOI: 10.1177/11206721221078152] [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: 11/16/2022]
Abstract
PURPOSE To report a case of corneal scarring following collagen cross linking in a young female. METHODS A 24-year-old female presented to us with complaints of decreased vision and a white spot in her left eye following collagen cross linking (CXL) performed elsewhere, four years prior. We diagnosed her as a case of left eye leucomatous corneal opacity for which she underwent optical penetrating keratoplasty under local anaesthesia. The excised corneal tissue was evaluated by routine histopathology and immunohistochemistry. RESULTS At the final follow up visit, one year following corneal transplantation, her visual acuity improved to 20/20, J1 with a clear graft. CONCLUSION Vision threatening corneal scarring may be rarely noted following CXL.
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Affiliation(s)
- Sushmita G Shah
- Cornea, Cataract & Refractive Surgery Services, Eye Life, Mumbai - 52, India
| | - Rohit Shetty
- Cornea & Refractive Surgery Services, 80219Narayana Nethralaya, Bengaluru, India
| | - Arkasubra Ghosh
- GROW Research Laboratory, 80219Narayana Nethralaya Foundation, Bengaluru, India
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Vaiciuliene R, Rylskyte N, Baguzyte G, Jasinskas V. Risk factors for fluctuations in corneal endothelial cell density (Review). Exp Ther Med 2022; 23:129. [PMID: 34970352 PMCID: PMC8713183 DOI: 10.3892/etm.2021.11052] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/29/2021] [Indexed: 12/17/2022] Open
Abstract
The cornea is a transparent, avascular and abundantly innervated tissue through which light rays are transmitted to the retina. The innermost layer of the cornea, also known as the endothelium, consists of a single layer of polygonal endothelial cells that serve an important role in preserving corneal transparency and hydration. The average corneal endothelial cell density (ECD) is the highest at birth (~3,000 cells/mm2), which then decrease to ~2,500 cells/mm2 at adulthood. These endothelial cells have limited regenerative potential and the minimum (critical) ECD required to maintain the pumping function of the endothelium is 400-500 cells/mm2. ECD < the critical value can result in decreased corneal transparency, development of corneal edema and reduced visual acuity. The condition of the corneal endothelium can be influenced by a number of factors, including systemic diseases, such as diabetes or atherosclerosis, eye diseases, such as uveitis or dry eye disease (DED) and therapeutic ophthalmological interventions. The aim of the present article is to review the impact of the most common systemic disorders (pseudoexfoliation syndrome, diabetes mellitus, cardiovascular disease), eye diseases (DED, uveitis, glaucoma, intraocular lens dislocation) and widely performed ophthalmic interventions (cataract surgery, intraocular pressure-lowering surgeries) on corneal ECD.
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Affiliation(s)
- Renata Vaiciuliene
- Department of Ophthalmology, Medical Academy, Lithuanian University of Health Sciences, LT-50161 Kaunas, Lithuania
| | - Neda Rylskyte
- Faculty of Medicine, Lithuanian University of Health Sciences, LT-44307 Kaunas, Lithuania
| | - Gabija Baguzyte
- Department of Ophthalmology, Medical Academy, Lithuanian University of Health Sciences, LT-50161 Kaunas, Lithuania
| | - Vytautas Jasinskas
- Department of Ophthalmology, Medical Academy, Lithuanian University of Health Sciences, LT-50161 Kaunas, Lithuania
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Collagen-Derived Peptides in CKD: A Link to Fibrosis. Toxins (Basel) 2021; 14:toxins14010010. [PMID: 35050988 PMCID: PMC8781252 DOI: 10.3390/toxins14010010] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/07/2021] [Accepted: 12/17/2021] [Indexed: 02/06/2023] Open
Abstract
Collagen is a major component of the extracellular matrix (ECM) and has an imminent role in fibrosis, in, among others, chronic kidney disease (CKD). Collagen alpha-1(I) (col1a1) is the most abundant collagen type and has previously been underlined for its contribution to the disease phenotype. Here, we examined 5000 urinary peptidomic datasets randomly selected from healthy participants or patients with CKD to identify urinary col1a1 fragments and study their abundance, position in the main protein, as well as their correlation with renal function. We identified 707 col1a1 peptides that differed in their amino acid sequence and/or post-translational modifications (hydroxyprolines). Well-correlated peptides with the same amino acid sequence, but a different number of hydroxyprolines, were combined into a final list of 503 peptides. These 503 col1a1 peptides covered 69% of the full col1a1 sequence. Sixty-three col1a1 peptides were significantly and highly positively associated (rho > +0.3) with the estimated glomerular filtration rate (eGFR), while only six peptides showed a significant and strong, negative association (rho < −0.3). A similar tendency was observed for col1a1 peptides associated with ageing, where the abundance of most col1a1 peptides decreased with increasing age. Collectively the results show a strong association between collagen peptides and loss of kidney function and suggest that fibrosis, potentially also of other organs, may be the main consequence of an attenuation of collagen degradation, and not increased synthesis.
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Sinha NR, Balne PK, Bunyak F, Hofmann AC, Lim RR, Mohan RR, Chaurasia SS. Collagen matrix perturbations in corneal stroma of Ossabaw mini pigs with type 2 diabetes. Mol Vis 2021; 27:666-678. [PMID: 35002212 PMCID: PMC8684810] [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: 04/02/2021] [Accepted: 12/05/2021] [Indexed: 11/17/2022] Open
Abstract
Purpose Diabetes mellitus (DM) is a metabolic disorder that affects over 450 million people worldwide. DM is characterized by hyperglycemia, causing severe systemic damage to the heart, kidneys, skin, vasculature, nerves, and eye. Type 2 diabetes (T2DM) constitutes 90% of clinical cases and is the most common cause of blindness in working adults. Also, about 70% of T2DM patients show corneal complications including delayed wound healing, often described as diabetic keratopathy (DK). Despite the increasing severity of DM, the research on DK is bleak. This study investigated cellular morphology and collagen matrix alterations of the diabetic and non-diabetic corneas collected from Ossabaw mini pigs, a T2DM animal model with a "thrifty genotype." Methods Pig corneas were collected from six-month-old Ossabaw miniature pigs fed on a western diet (WD) for ten weeks. The tissues were processed for immunohistochemistry and analyzed using hematoxylin and eosin staining, Mason Trichrome staining, Picrosirus Red staining, Collage I staining, and TUNEL assay. mRNA was prepared to quantify fibrotic gene expression using quantitative reverse-transcriptase PCR (qRT-PCR). Transmission electron microscopy (TEM) was performed to evaluate stromal fibril arrangements to compare collagen dynamics in WD vs. standard diet (SD) fed Ossabaw pig corneas. Results Ossabaw mini pigs fed on a WD for 10 weeks exhibit classic symptoms of metabolic syndrome and hyperglycemia seen in T2DM patients. We observed significant disarray in cornea stromal collagen matrix in Ossabaw mini pigs fed on WD compared to the age-matched mini pigs fed on a standard chow diet using Masson Trichome and Picrosirius Red staining. Furthermore, ultrastructure evaluation using TEM showed alterations in stromal collagen fibril size and organization in diabetic corneas compared to healthy age-matched corneas. These changes were accompanied by significantly decreased levels of Collagen IV and increased expression of matrix metallopeptidase 9 in WD-fed pigs. Conclusions This pilot study indicates that Ossabaw mini pigs fed on WD showed collagen disarray and altered gene expression involved in wound healing, suggesting that corneal stromal collagens are vulnerable to diabetic conditions.
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Affiliation(s)
- Nishant R. Sinha
- Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO
- One-Health Vision Research Program, Departments of Ophthalmology and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - Praveen K. Balne
- Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO
- One-Health Vision Research Program, Departments of Ophthalmology and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - Filiz Bunyak
- Department of Computer Science, University of Missouri, Columbia, MO
| | - Alexandria C. Hofmann
- One-Health Vision Research Program, Departments of Ophthalmology and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - Rayne R. Lim
- Department of Ophthalmology, University of Washington, Seattle, WA
| | - Rajiv R. Mohan
- Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO
- One-Health Vision Research Program, Departments of Ophthalmology and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO
- Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO
| | - Shyam S. Chaurasia
- One-Health Vision Research Program, Departments of Ophthalmology and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO
- Department of Ophthalmology and Visual Sciences, The Eye Institute, Medical College of Wisconsin, Milwaukee, WI
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Middendorf JM, Ita ME, Winkelstein BA, H Barocas V. Local tissue heterogeneity may modulate neuronal responses via altered axon strain fields: insights about innervated joint capsules from a computational model. Biomech Model Mechanobiol 2021; 20:2269-2285. [PMID: 34514531 PMCID: PMC9289994 DOI: 10.1007/s10237-021-01506-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/12/2021] [Indexed: 02/08/2023]
Abstract
In innervated collagenous tissues, tissue scale loading may contribute to joint pain by transmitting force through collagen fibers to the embedded mechanosensitive axons. However, the highly heterogeneous collagen structures of native tissues make understanding this relationship challenging. Recently, collagen gels with embedded axons were stretched and the resulting axon signals were measured, but these experiments were unable to measure the local axon strain fields. Computational discrete fiber network models can directly determine axon strain fields due to tissue scale loading. Therefore, this study used a discrete fiber network model to identify how heterogeneous collagen networks (networks with multiple collagen fiber densities) change axon strain due to tissue scale loading. In this model, a composite cylinder (axon) was embedded in a Delaunay network (collagen). Homogeneous networks with a single collagen volume fraction and two types of heterogeneous networks with either a sparse center or dense center were created. Measurements of fiber forces show higher magnitude forces in sparse regions of heterogeneous networks and uniform force distributions in homogeneous networks. The average axon strain in the sparse center networks decreases when compared to homogeneous networks with similar collagen volume fractions. In dense center networks, the average axon strain increases compared to homogeneous networks. The top 1% of axon strains are unaffected by network heterogeneity. Based on these results, the interaction of tissue scale loading, collagen network heterogeneity, and axon strains in native musculoskeletal tissues should be considered when investigating the source of joint pain.
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Affiliation(s)
- Jill M Middendorf
- Department of Biomedical Engineering, College of Science and Engineering, University of Minnesota, Nils Hasselmo Hall, 312 Church St SE, Minneapolis, MN, USA
| | - Meagan E Ita
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Beth A Winkelstein
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Victor H Barocas
- Department of Biomedical Engineering, College of Science and Engineering, University of Minnesota, Nils Hasselmo Hall, 312 Church St SE, Minneapolis, MN, USA.
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Ates KM, Estes AJ, Liu Y. Potential underlying genetic associations between keratoconus and diabetes mellitus. ADVANCES IN OPHTHALMOLOGY PRACTICE AND RESEARCH 2021; 1:100005. [PMID: 34746916 PMCID: PMC8570550 DOI: 10.1016/j.aopr.2021.100005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/18/2021] [Accepted: 08/29/2021] [Indexed: 12/14/2022]
Abstract
Background Keratoconus (KC) is the most common ectatic corneal disease, characterized by significantly localized thinning of the corneal stroma. Genetic, environmental, hormonal, and metabolic factors contribute to the pathogenesis of KC. Additionally, multiple comorbidities, such as diabetes mellitus, may affect the risk of KC. Main Body Patients with diabetes mellitus (DM) have been reported to have lower risk of developing KC by way of increased endogenous collagen crosslinking in response to chronic hyperglycemia. However, this remains a debated topic as other studies have suggested either a positive association or no association between DM and KC. To gain further insight into the underlying genetic components of these two diseases, we reviewed candidate genes associated with KC and central corneal thickness in the literature. We then explored how these genes may be regulated similarly or differentially under hyperglycemic conditions and the role they play in the systemic complications associated with DM. Conclusion Our comprehensive review of potential genetic factors underlying KC and DM provides a direction for future studies to further determine the genetic etiology of KC and how it is influenced by systemic diseases such as diabetes.
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Affiliation(s)
- Kristin M. Ates
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Amy J. Estes
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA, USA
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Yutao Liu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA, USA
- James and Jean Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, GA, USA
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, Augusta University, Augusta, GA, USA
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Feng L, Liu R, Zhang X, Li J, Zhu L, Li Z, Li W, Zhang A. Thermo-Gelling Dendronized Chitosans as Biomimetic Scaffolds for Corneal Tissue Engineering. ACS APPLIED MATERIALS & INTERFACES 2021; 13:49369-49379. [PMID: 34636236 DOI: 10.1021/acsami.1c16087] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Biomimetic scaffolds with transparent, biocompatible, and in situ-forming properties are highly desirable for corneal tissue engineering, which can deeply fill corneal stromal defects with irregular shapes and support tissue regeneration. We here engineer a novel class of corneal scaffolds from oligoethylene glycol (OEG)-based dendronized chitosans (DCs), whose aqueous solutions show intriguing sol-gel transitions triggered by physiological temperature, resulting in highly transparent hydrogels. Gelling points of these hydrogels can be easily tuned, and furthermore, their mechanical strengths can be significantly enhanced when injected into PBS at 37 °C instead of pure water. In vitro tests indicate that these DC hydrogels exhibit excellent biocompatibility and can promote proliferation and migration of keratocyte. When applied in the rabbit eyes with corneal stromal defects, in situ formed DC hydrogels play a positive effect for new tissue regeneration. Overall, this thermo-gelling DCs possess appealing features as corneal tissue substitutes with their excellent biocompatibility and unprecedented thermoresponsiveness.
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Affiliation(s)
- Letian Feng
- International Joint Laboratory of Biomimetic and Smart Polymers, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Ruixing Liu
- Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou 450003, China
| | - Xiacong Zhang
- International Joint Laboratory of Biomimetic and Smart Polymers, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Jingguo Li
- Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou 450003, China
| | - Lei Zhu
- Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou 450003, China
| | - Zhanrong Li
- Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou 450003, China
| | - Wen Li
- International Joint Laboratory of Biomimetic and Smart Polymers, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
| | - Afang Zhang
- International Joint Laboratory of Biomimetic and Smart Polymers, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
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Abstract
One of the most important functions of the skin, i.e., protection from mechanical damage, is ensured by collagen fibers and their interaction with other elements in the extracellular matrix. Collagen fiber turnover is a complex multi-stage process. At each stage, a disruption may occur, leading to a decrease in the mechanical properties of the connective tissue. Clinically, collagen formation disorders manifest themselves as increased flabbiness and looseness of the skin and as early signs of facial aging. In addition to the clinical picture, it is important for cosmetologists and dermatologists to understand the etiology and pathogenesis of collagenopathies. In our review, we summarized and systematized the available information concerning the role of genetic and epigenetic factors in skin collagen fiber turnover. Furthermore, we focused on the functions of different types of collagens present in the skin. Understanding the etiology of impaired collagen formation can allow doctors to prescribe pathogenetically based treatments, achieve the most effective results, and minimize adverse reactions.
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Onyibe PN, Edo GI, Nwosu LC, Ozgor E. Effects of vernonia amygdalina fractionate on glutathione reductase and glutathione-S-transferase on alloxan induced diabetes wistar rat. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2021. [DOI: 10.1016/j.bcab.2021.102118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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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] [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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Blackburn BJ, Rollins AM, Dupps WJ. Biomechanics of Ophthalmic Crosslinking. Transl Vis Sci Technol 2021; 10:8. [PMID: 34328498 PMCID: PMC8327749 DOI: 10.1167/tvst.10.5.8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 06/19/2021] [Indexed: 12/12/2022] Open
Abstract
Crosslinking involves the formation of bonds between polymer chains, such as proteins. In biological tissues, these bonds tend to stiffen the tissue, making it more resistant to mechanical degradation and deformation. In ophthalmology, the crosslinking phenomenon is being increasingly harnessed and explored as a treatment strategy for treating corneal ectasias, keratitis, degenerative myopia, and glaucoma. This review surveys the multitude of exogenous crosslinking strategies reported in the literature, both "light" (involving light energy) and "dark" (involving non-photic chemical processes), and explores their mechanisms, cytotoxicity, and stage of translational development. The spectrum of ophthalmic applications described in the literature is then discussed, with particular attention to proposed therapeutic mechanisms in the cornea and sclera. The mechanical effects of crosslinking are then discussed in the context of their proposed site and scale of action. Biomechanical characterization of the crosslinking effect is needed to more thoroughly address knowledge gaps in this area, and a review of reported methods for biomechanical characterization is presented with an attempt to assess the sensitivity of each method to crosslinking-mediated changes using data from the experimental and clinical literature. Biomechanical measurement methods differ in spatial resolution, mechanical sensitivity, suitability for detecting crosslinking subtypes, and translational readiness and are central to the effort to understand the mechanistic link between crosslinking methods and clinical outcomes of candidate therapies. Data on differences in the biomechanical effect of different crosslinking protocols and their correspondence to clinical outcomes are reviewed, and strategies for leveraging measurement advances predicting clinical outcomes of crosslinking procedures are discussed. Advancing the understanding of ophthalmic crosslinking, its biomechanical underpinnings, and its applications supports the development of next-generation crosslinking procedures that optimize therapeutic effect while reducing complications.
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Affiliation(s)
- Brecken J. Blackburn
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Andrew M. Rollins
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - William J. Dupps
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
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Shah R, Amador C, Tormanen K, Ghiam S, Saghizadeh M, Arumugaswami V, Kumar A, Kramerov AA, Ljubimov AV. Systemic diseases and the cornea. Exp Eye Res 2021; 204:108455. [PMID: 33485845 PMCID: PMC7946758 DOI: 10.1016/j.exer.2021.108455] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 01/08/2023]
Abstract
There is a number of systemic diseases affecting the cornea. These include endocrine disorders (diabetes, Graves' disease, Addison's disease, hyperparathyroidism), infections with viruses (SARS-CoV-2, herpes simplex, varicella zoster, HTLV-1, Epstein-Barr virus) and bacteria (tuberculosis, syphilis and Pseudomonas aeruginosa), autoimmune and inflammatory diseases (rheumatoid arthritis, Sjögren's syndrome, lupus erythematosus, gout, atopic and vernal keratoconjunctivitis, multiple sclerosis, granulomatosis with polyangiitis, sarcoidosis, Cogan's syndrome, immunobullous diseases), corneal deposit disorders (Wilson's disease, cystinosis, Fabry disease, Meretoja's syndrome, mucopolysaccharidosis, hyperlipoproteinemia), and genetic disorders (aniridia, Ehlers-Danlos syndromes, Marfan syndrome). Corneal manifestations often provide an insight to underlying systemic diseases and can act as the first indicator of an undiagnosed systemic condition. Routine eye exams can bring attention to potentially life-threatening illnesses. In this review, we provide a fairly detailed overview of the pathologic changes in the cornea described in various systemic diseases and also discuss underlying molecular mechanisms, as well as current and emerging treatments.
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Affiliation(s)
- Ruchi Shah
- Eye Program, Board of Governors Regenerative Medicine Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
| | - Cynthia Amador
- Eye Program, Board of Governors Regenerative Medicine Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Kati Tormanen
- Center for Neurobiology and Vaccine Development, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Sean Ghiam
- Sackler School of Medicine, New York State/American Program of Tel Aviv University, Tel Aviv, Israel
| | - Mehrnoosh Saghizadeh
- Eye Program, Board of Governors Regenerative Medicine Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA; Departments of Molecular and Medical Pharmacology, Medicine, and Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Vaithi Arumugaswami
- Departments of Molecular and Medical Pharmacology, Medicine, and Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Ashok Kumar
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University, Detroit, MI, USA
| | - Andrei A Kramerov
- Eye Program, Board of Governors Regenerative Medicine Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Alexander V Ljubimov
- Eye Program, Board of Governors Regenerative Medicine Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, USA; Departments of Molecular and Medical Pharmacology, Medicine, and Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
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Regenerative and Antioxidant Properties of Autologous Platelet-Rich Plasma Can Reserve the Aging Process of the Cornea in the Rat Model. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:4127959. [PMID: 33299525 PMCID: PMC7704147 DOI: 10.1155/2020/4127959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 09/14/2020] [Accepted: 11/07/2020] [Indexed: 12/19/2022]
Abstract
Aging is a natural progressive decline in the biological function of cells. Age-related changes in the cornea can affect its ability to refract light or repair itself. Platelet-rich plasma (PRP) has a promising role in regenerative medicine and evidenced its efficacy in multiple fields, but in corneal aging has not yet been elucidated. The present work was performed to estimate the regenerative antioxidant effect of PRP on corneal aging in rats. Rats were assigned into two main groups: (GI) adult group and (GII) aged group. The adult group was divided into GIa (adult rats), GIb (adult-saline treated), and GIc (adult-PRP treated). The aged group was divided into GIIa (aged rats) and GIIb (aged, PRP treated). PRP was administered by a single subconjunctival injection. After 10 days, histological, ultrastructural, immunohistochemical, and morphometrical investigations were carried out. Examination of the corneal sections of the aged group revealed corneal epithelial thinning, shedding of the surface epithelium with loss of desmosomal junction, and irregularity in Bowman's membrane. Disorganized widely spaced collagen bundles and neovascularization were detected in corneal stroma associated with thickening in Descemet's membrane. Ultrastructural examination revealed shrunken hyperchromatic nuclei, swollen mitochondria, and scanty cytoplasm with a strong nuclear reaction for caspase-3 immunostaining. Moreover, antioxidant/free radicals' imbalance was detected by the increase of malondialdehyde (MDA) level with a decrease of glutathione peroxidase (GPx) and superoxide dismutase (SOD) levels. In contrast, GIIb (aged, PRP treated) section examination revealed a restoration of the thickness of the corneal epithelial layer and Descemet's membrane with an amendment of collagen fiber regularity that is associated with weak nuclear reaction to caspase-3 and recovery of the balance in the redox state. These findings proved the effectiveness of PRP as a promising regenerative treatment for the age-associated changes in the cornea.
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Priyadarsini S, Whelchel A, Nicholas S, Sharif R, Riaz K, Karamichos D. Diabetic keratopathy: Insights and challenges. Surv Ophthalmol 2020; 65:513-529. [PMID: 32092364 PMCID: PMC8116932 DOI: 10.1016/j.survophthal.2020.02.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 02/10/2020] [Accepted: 02/11/2020] [Indexed: 12/11/2022]
Abstract
Ocular complications from diabetes mellitus are common. Diabetic keratopathy, the most frequent clinical condition affecting the human cornea, is a potentially sight-threatening condition caused mostly by epithelial disturbances that are of clinical and research attention because of their severity. Diabetic keratopathy exhibits several clinical manifestations, including persistent corneal epithelial erosion, superficial punctate keratopathy, delayed epithelial regeneration, and decreased corneal sensitivity, that may lead to compromised visual acuity or permanent vision loss. The limited amount of clinical studies makes it difficult to fully understand the pathobiology of diabetic keratopathy. Effective therapeutic approaches are elusive. We summarize the clinical manifestations of diabetic keratopathy and discuss available treatments and up-to-date research studies in an attempt to provide a thorough overview of the disorder.
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Affiliation(s)
- S Priyadarsini
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - A Whelchel
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - S Nicholas
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - R Sharif
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - K Riaz
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - D Karamichos
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA; Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA.
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Xu P, Londregan A, Rich C, Trinkaus-Randall V. Changes in Epithelial and Stromal Corneal Stiffness Occur with Age and Obesity. Bioengineering (Basel) 2020; 7:bioengineering7010014. [PMID: 32046198 PMCID: PMC7175307 DOI: 10.3390/bioengineering7010014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 01/29/2020] [Accepted: 02/04/2020] [Indexed: 01/18/2023] Open
Abstract
The cornea is avascular, which makes it an excellent model to study matrix protein expression and tissue stiffness. The corneal epithelium adheres to the basement zone and the underlying stroma is composed of keratocytes and an extensive matrix of collagen and proteoglycans. Our goal was to examine changes in corneas of 8- and 15-week mice and compare them to 15-week pre-Type 2 diabetic obese mouse. Nanoindentation was performed on corneal epithelium in situ and then the epithelium was abraded, and the procedure repeated on the basement membrane and stroma. Confocal imaging was performed to examine the localization of proteins. Stiffness was found to be age and obesity dependent. Young’s modulus was greater in the epithelium from 15-week mice compared to 8-week mice. At 15 weeks, the epithelium of the control was significantly greater than that of the obese mice. There was a difference in the localization of Crb3 and PKCζ in the apical epithelium and a lack of lamellipodial extensions in the obese mouse. In the pre-Type 2 diabetic obese mouse there was a difference in the stiffness slope and after injury localization of fibronectin was negligible. These indicate that age and environmental changes incurred by diet alter the integrity of the tissue with age rendering it stiffer. The corneas from the pre-Type 2 diabetic obese mice were significantly softer and this may be a result of changes both in proteins on the apical surface indicating a lack of integrity and a decrease in fibronectin.
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Affiliation(s)
- Peiluo Xu
- Department of Biomedical Engineering, Boston University, Boston, MA 02115, USA;
| | - Anne Londregan
- Department of Biochemistry/Molecular Biology, Boston University, Boston, MA 02215, USA;
| | - Celeste Rich
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02115, USA;
| | - Vickery Trinkaus-Randall
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02115, USA;
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA 02115, USA
- Correspondence:
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