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Courson JA, Rumbaut RE, Burns AR. Impact of Obesity and Age on Mouse Corneal Innervation at the Epithelial-Stromal Interface. Invest Ophthalmol Vis Sci 2024; 65:11. [PMID: 38709524 PMCID: PMC11078165 DOI: 10.1167/iovs.65.5.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 04/23/2024] [Indexed: 05/07/2024] Open
Abstract
Purpose The corneal epithelium is the most highly innervated structure in the body. Previously, we reported a novel event whereby stromal axons fuse with basal epithelial cells, limiting nerve penetration into the epithelium. Although corneal-epithelial nerves undergo changes in sensitivity and distribution throughout life and in response to an obesogenic diet, it is unknown if neuronal-epithelial cell fusion is altered. Here, we sought to determine if neuronal-epithelial cell fusion frequency correlates with obesogenic diet consumption and age. Methods Corneas were collected from C57BL/6 mice and evaluated for neuronal-epithelial cell fusion frequency using serial block-face scanning electron microscopy. To assess the correlation between diet-induced obesity and fusion frequency, 6-week-old mice were fed either a normal diet or an obesogenic diet for 10 weeks. To assess changes in fusion frequency between young and adult mice under normal dietary conditions, 9- and 24-week-old mice were used. Results Mice fed a 10-week obesogenic diet showed 87% of central-cornea stromal nerves engaged in fusion compared with only 54% in age-matched controls (16 weeks old). In 9-week-old normal-diet animals, 48% of central-cornea stromal nerves contained fusing axons and increased to 81% at 24 weeks of age. Corneal sensitivity loss correlated with increased body weight and adiposity regardless of age and diet. Conclusions Neuronal-epithelial cell fusion positively correlates with age and obesogenic diet consumption, and corneal nerve sensitivity loss correlates with increased body weight and adiposity, regardless of age and diet. As such, neuronal-epithelial cell fusion may play a role in corneal nerve density and sensitivity regulation.
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Affiliation(s)
- Justin A. Courson
- Department of Medicine, Baylor College of Medicine, Houston, Texas, United States
- Center for Translational Research on Inflammatory Diseases, Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States
| | - Rolando E. Rumbaut
- Department of Medicine, Baylor College of Medicine, Houston, Texas, United States
- Center for Translational Research on Inflammatory Diseases, Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas, United States
| | - Alan R. Burns
- College of Optometry, University of Houston, Houston, Texas, United States
- Children's Nutrition Center, Baylor College of Medicine, Houston, Texas, United States
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Azzari NA, Segars KL, Rapaka S, Kushimi L, Rich CB, Trinkaus-Randall V. Aberrations in Cell Signaling Quantified in Diabetic Murine Globes after Injury. Cells 2023; 13:26. [PMID: 38201230 PMCID: PMC10778404 DOI: 10.3390/cells13010026] [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: 11/01/2023] [Revised: 12/12/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024] Open
Abstract
The corneal epithelium is an avascular structure that has a unique wound healing mechanism, which allows for rapid wound closure without compromising vision. This wound healing mechanism is attenuated in diabetic patients, resulting in poor clinical outcomes and recurrent non-healing erosion. We investigated changes in cellular calcium signaling activity during the wound response in murine diabetic tissue using live cell imaging from both ex vivo and in vitro models. The calcium signaling propagation in diabetic cells was significantly decreased and displayed altered patterns compared to non-diabetic controls. Diabetic cells and tissue display distinct expression of the purinergic receptor, P2X7, which mediates the wound healing response. We speculate that alterations in P2X7 expression, interactions with other proteins, and calcium signaling activity significantly impact the wound healing response. This may explain aberrations in the diabetic wound response.
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Affiliation(s)
- Nicholas A. Azzari
- Department of Biochemistry and Cell Biology, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA; (N.A.A.); (C.B.R.)
| | - Kristen L. Segars
- Department of Pharmacology, Physiology and Biophysics, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA;
| | - Srikar Rapaka
- Department of Medicine, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA;
| | - Landon Kushimi
- Department of Computer Science, Center for Computing and Data Sciences, Boston University, 665 Commonwealth Ave, Boston, MA 02115, USA;
| | - Celeste B. Rich
- Department of Biochemistry and Cell Biology, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA; (N.A.A.); (C.B.R.)
| | - Vickery Trinkaus-Randall
- Department of Biochemistry and Cell Biology, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA; (N.A.A.); (C.B.R.)
- Department of Pharmacology, Physiology and Biophysics, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA;
- Department of Ophthalmology, Boston University Chobanian and Avedisian School of Medicine, 72 E. Concord St., Boston, MA 02118, USA
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Machet J, Park M, Richardson A, Carnell M, Mouat MA, Smith NJ, Turner N, Cochran BJ, Rye KA, Di Girolamo N. Type 2 diabetes influences intraepithelial corneal nerve parameters and corneal stromal-epithelial nerve penetration sites. J Diabetes Investig 2023; 14:591-601. [PMID: 36727569 PMCID: PMC10034950 DOI: 10.1111/jdi.13974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/16/2022] [Accepted: 01/01/2023] [Indexed: 02/03/2023] Open
Abstract
INTRODUCTION The quantification of intraepithelial corneal basal nerve parameters by in vivo confocal microscopy represents a promising modality to identify the earliest manifestations of diabetic peripheral neuropathy. However, its diagnostic accuracy is hampered by its dependence on neuron length, with minimal consideration for other parameters, including the origin of these nerves, the corneal stromal-epithelial nerve penetration sites. This study sought to utilize high-resolution images of murine corneal nerves to analyze comprehensively the morphological changes associated with type 2 diabetes progression. MATERIALS AND METHODS βIII-Tubulin immunostained corneas from prediabetic and type 2 diabetic mice and their respective controls were imaged by scanning confocal microscopy and analyzed automatically for nerve parameters. Additionally, the number and distribution of penetration sites was manually ascertained and the average length of the axons exiting them was computed. RESULTS The earliest detectable changes included a significant increase in nerve density (6.06 ± 0.41% vs 8.98 ± 1.99%, P = 0.03) and branching (2867.8 ± 271.3/mm2 vs 4912.1 ± 1475.3/mm2 , P = 0.03), and in the number of penetration sites (258.80 ± 20.87 vs 422.60 ± 63.76, P = 0.0002) at 8 weeks of age. At 16 weeks, corneal innervation decreased, most notably in the periphery. The number of penetration sites remained significantly elevated relative to controls throughout the monitoring period. Similarly, prediabetic mice exhibited an increased number of penetration sites (242.2 ± 13.55 vs 305.6 ± 30.96, P = 0.003) without significant changes to the nerves. CONCLUSIONS Our data suggest that diabetic peripheral neuropathy may be preceded by a phase of neuron growth rather than regression, and that the peripheral cornea is more sensitive than the center for detecting changes in innervation.
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Affiliation(s)
- Joshua Machet
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Mijeong Park
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Alexander Richardson
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Michael Carnell
- Katharina Gaus Light Microscopy Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW, Australia
| | - Margaret A Mouat
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Nicola J Smith
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Nigel Turner
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
- Victor Chang Cardiac Research Institute, Sydney, NSW, Australia
| | - Blake J Cochran
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Kerry-Anne Rye
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Nick Di Girolamo
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
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Liang W, Huang L, Whelchel A, Yuan T, Ma X, Cheng R, Takahashi Y, Karamichos D, Ma JX. Peroxisome proliferator-activated receptor-α (PPARα) regulates wound healing and mitochondrial metabolism in the cornea. Proc Natl Acad Sci U S A 2023; 120:e2217576120. [PMID: 36943878 PMCID: PMC10068757 DOI: 10.1073/pnas.2217576120] [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: 10/14/2022] [Accepted: 02/14/2023] [Indexed: 03/23/2023] Open
Abstract
Diabetes can result in impaired corneal wound healing. Mitochondrial dysfunction plays an important role in diabetic complications. However, the regulation of mitochondria function in the diabetic cornea and its impacts on wound healing remain elusive. The present study aimed to explore the molecular basis for the disturbed mitochondrial metabolism and subsequent wound healing impairment in the diabetic cornea. Seahorse analysis showed that mitochondrial oxidative phosphorylation is a major source of ATP production in human corneal epithelial cells. Live corneal biopsy punches from type 1 and type 2 diabetic mouse models showed impaired mitochondrial functions, correlating with impaired corneal wound healing, compared to nondiabetic controls. To approach the molecular basis for the impaired mitochondrial function, we found that Peroxisome Proliferator-Activated Receptor-α (PPARα) expression was downregulated in diabetic human corneas. Even without diabetes, global PPARα knockout mice and corneal epithelium-specific PPARα conditional knockout mice showed disturbed mitochondrial function and delayed wound healing in the cornea, similar to that in diabetic corneas. In contrast, fenofibrate, a PPARα agonist, ameliorated mitochondrial dysfunction and enhanced wound healing in the corneas of diabetic mice. Similarly, corneal epithelium-specific PPARα transgenic overexpression improved mitochondrial function and enhanced wound healing in the cornea. Furthermore, PPARα agonist ameliorated the mitochondrial dysfunction in primary human corneal epithelial cells exposed to diabetic stressors, which was impeded by siRNA knockdown of PPARα, suggesting a PPARα-dependent mechanism. These findings suggest that downregulation of PPARα plays an important role in the impaired mitochondrial function in the corneal epithelium and delayed corneal wound healing in diabetes.
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Affiliation(s)
- Wentao Liang
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK73104
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC27157
| | - Li Huang
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC27157
- Department of Ophthalmology, Fujian Medical University Union Hospital, Fuzhou350000, China
| | - Amy Whelchel
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK73104
| | - Tian Yuan
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC27157
| | - Xiang Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK73104
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC27157
| | - Rui Cheng
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC27157
| | - Yusuke Takahashi
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC27157
| | - Dimitrios Karamichos
- Division of Research and Innovation, North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX76107
- Department of Pharmaceutical Sciences, University of North Texas Health Science Center, Fort Worth, TX76107
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX76107
| | - Jian-Xing Ma
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC27157
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Yu FSX, Lee PSY, Yang L, Gao N, Zhang Y, Ljubimov AV, Yang E, Zhou Q, Xie L. The impact of sensory neuropathy and inflammation on epithelial wound healing in diabetic corneas. Prog Retin Eye Res 2022; 89:101039. [PMID: 34991965 PMCID: PMC9250553 DOI: 10.1016/j.preteyeres.2021.101039] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 12/10/2021] [Accepted: 12/20/2021] [Indexed: 02/08/2023]
Abstract
Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes, with several underlying pathophysiological mechanisms, some of which are still uncertain. The cornea is an avascular tissue and sensitive to hyperglycemia, resulting in several diabetic corneal complications including delayed epithelial wound healing, recurrent erosions, neuropathy, loss of sensitivity, and tear film changes. The manifestation of DPN in the cornea is referred to as diabetic neurotrophic keratopathy (DNK). Recent studies have revealed that disturbed epithelial-neural-immune cell interactions are a major cause of DNK. The epithelium is supplied by a dense network of sensory nerve endings and dendritic cell processes, and it secretes growth/neurotrophic factors and cytokines to nourish these neighboring cells. In turn, sensory nerve endings release neuropeptides to suppress inflammation and promote epithelial wound healing, while resident immune cells provide neurotrophic and growth factors to support neuronal and epithelial cells, respectively. Diabetes greatly perturbs these interdependencies, resulting in suppressed epithelial proliferation, sensory neuropathy, and a decreased density of dendritic cells. Clinically, this results in a markedly delayed wound healing and impaired sensory nerve regeneration in response to insult and injury. Current treatments for DPN and DNK largely focus on managing the severe complications of the disease. Cell-based therapies hold promise for providing more effective treatment for diabetic keratopathy and corneal ulcers.
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Affiliation(s)
- Fu-Shin X Yu
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, 48201, USA.
| | - Patrick S Y Lee
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Lingling Yang
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, China
| | - Nan Gao
- Departments of Ophthalmology and Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI, 48201, USA
| | - Yangyang Zhang
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, China
| | - Alexander V Ljubimov
- Departments of Biomedical Sciences and Neurosurgery, Cedars-Sinai Medical Center, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Ellen Yang
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, 60064, USA
| | - Qingjun Zhou
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, China
| | - Lixin Xie
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, China.
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Segars KL, Azzari NA, Gomez S, Machen C, Rich CB, Trinkaus-Randall V. Age Dependent Changes in Corneal Epithelial Cell Signaling. Front Cell Dev Biol 2022; 10:886721. [PMID: 35602595 PMCID: PMC9117764 DOI: 10.3389/fcell.2022.886721] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/19/2022] [Indexed: 11/25/2022] Open
Abstract
The cornea is exposed daily to a number of mechanical stresses including shear stress from tear film and blinking. Over time, these stressors can lead to changes in the extracellular matrix that alter corneal stiffness, cell-substrate structures, and the integrity of cell-cell junctions. We hypothesized that changes in tissue stiffness of the cornea with age may alter calcium signaling between cells after injury, and the downstream effects of this signaling on cellular motility and wound healing. Nanoindentation studies revealed that there were significant differences in the stiffness of the corneal epithelium and stroma between corneas of 9- and 27-week mice. These changes corresponded to differences in the timeline of wound healing and in cell signaling. Corneas from 9-week mice were fully healed within 24 h. However, the wounds on corneas from 27-week mice remained incompletely healed. Furthermore, in the 27-week cohort there was no detectable calcium signaling at the wound in either apical or basal corneal epithelial cells. This is in contrast to the young cohort, where there was elevated basal cell activity relative to background levels. Cell culture experiments were performed to assess the roles of P2Y2, P2X7, and pannexin-1 in cellular motility during wound healing. Inhibition of P2Y2, P2X7, or pannexin-1 all significantly reduce wound closure. However, the inhibitors all have different effects on the trajectories of individual migrating cells. Together, these findings suggest that there are several significant differences in the stiffness and signaling that underlie the decreased wound healing efficacy of the cornea in older mice.
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Affiliation(s)
- Kristen L. Segars
- Department of Pharmacology, School of Medicine, Boston University, Boston, MA, United States
| | - Nicholas A. Azzari
- Department of Biochemistry, School of Medicine, Boston University, Boston, MA, United States
| | - Stephanie Gomez
- Department of Biochemistry, School of Medicine, Boston University, Boston, MA, United States
| | - Cody Machen
- Department of Biochemistry, School of Medicine, Boston University, Boston, MA, United States
| | - Celeste B. Rich
- Department of Ophthalmology, School of Medicine, School of Medicine, Boston, MA, United States
| | - Vickery Trinkaus-Randall
- Department of Biochemistry, School of Medicine, Boston University, Boston, MA, United States
- Department of Ophthalmology, School of Medicine, School of Medicine, Boston, MA, United States
- *Correspondence: Vickery Trinkaus-Randall,
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7
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Bu Y, Shih KC, Tong L. The ocular surface and diabetes, the other 21st Century epidemic. Exp Eye Res 2022; 220:109099. [DOI: 10.1016/j.exer.2022.109099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 11/25/2022]
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Pannexin1: Role as a Sensor to Injury Is Attenuated in Pretype 2 Corneal Diabetic Epithelium. ACTA ACUST UNITED AC 2021; 2021:4793338. [PMID: 34336553 PMCID: PMC8295002 DOI: 10.1155/2021/4793338] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 07/07/2021] [Indexed: 11/17/2022]
Abstract
Epithelial wound healing is essential to repair the corneal barrier function after injury and requires coordinated epithelial sheet movement over the wounded region. The presence and role of pannexin1 on multilayered epithelial sheet migration was examined in unwounded and wounded corneal epithelium from C57BL/6J (B6) control and diet-induced obese (DiO) mice, a pretype 2 diabetic model. We hypothesize that pannexin1 is dysregulated, and the interaction of two ion-channel proteins (P2X7 and pannexin1) is altered in pretype 2 diabetic tissue. Pannexin1 was found to be present along cell borders in unwounded tissue, and no significant difference was observed between DiO and B6 control. However, an epithelial debridement induced a striking difference in pannexin1 localization. The B6 control epithelium displayed intense staining near the leading edge, which is the region where calcium mobilization was detected, whereas the staining in the DiO corneal epithelium was diffuse and lacked distinct gradation in intensity back from the leading edge. Cells distal to the wound in the DiO tissue were irregular in shape, and the morphology was similar to that of epithelium inhibited with 10Panx, a pannexin1 inhibitor. Pannexin1 inhibition reduced mobilization of calcium between cells near the leading edge, and MATLAB scripts revealed a reduction in cell-cell communication that was also detected in cultured cells. Proximity ligation was performed to determine if P2X7 and pannexin1 interaction was a necessary component of motility and communication. While there was no significant difference in the interaction in unwounded DiO and B6 control corneal epithelium, there was significantly less interaction in the wounded DiO corneas both near the wound and back from the edge. The results demonstrate that pannexin1 contributes to the healing response, and P2X7 and pannexin1 coordination may be a required component of cell-cell communication and an underlying reason for the lack of pathologic tissue migration.
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Lavker RM, Kaplan N, McMahon KM, Calvert AE, Henrich SE, Onay UV, Lu KQ, Peng H, Thaxton CS. Synthetic high-density lipoprotein nanoparticles: Good things in small packages. Ocul Surf 2021; 21:19-26. [PMID: 33894397 PMCID: PMC8328934 DOI: 10.1016/j.jtos.2021.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/26/2021] [Accepted: 03/06/2021] [Indexed: 12/26/2022]
Abstract
Medicine has been a great beneficiary of the nanotechnology revolution. Nanotechnology involves the synthesis of functional materials with at least one size dimension between 1 and 100 nm. Advances in the field have enabled the synthesis of bio-nanoparticles that can interface with physiological systems to modulate fundamental cellular processes. One example of a diverse acting nanoparticle-based therapeutic is synthetic high-density lipoprotein (HDL) nanoparticles (NP), which have great potential for treating diseases of the ocular surface. Our group has developed a spherical HDL NP using a gold nanoparticle core. HDL NPs: (i) closely mimic the physical and chemical features of natural HDLs; (ii) contain apoA-I; (iii) bind with high-affinity to SR-B1, which is the major receptor through which HDL modulates cell cholesterol metabolism and controls the selective uptake of HDL cargo into cells; (iv) are non-toxic to cells and tissues; and (v) can be chemically engineered to display nearly any surface or core composition desired. With respect to the ocular surface, topical application of HDL NPs accelerates re-epithelization of the cornea following wounding, attenuates inflammation resulting from chemical burns and/or other stresses, and effectively delivers microRNAs with biological activity to corneal cells and tissues. HDL NPs will be the foundation of a new class of topical eye drops with great translational potential and exemplify the impact that nanoparticles can have in medicine.
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Affiliation(s)
- Robert M Lavker
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
| | - Nihal Kaplan
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Kaylin M McMahon
- Department of Dermatology Urology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Andrea E Calvert
- Department of Dermatology Urology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Stephen E Henrich
- Department of Dermatology Urology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Ummiye V Onay
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Kurt Q Lu
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Han Peng
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - C Shad Thaxton
- Department of Dermatology Urology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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10
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Petropoulos IN, Ponirakis G, Ferdousi M, Azmi S, Kalteniece A, Khan A, Gad H, Bashir B, Marshall A, Boulton AJM, Soran H, Malik RA. Corneal Confocal Microscopy: A Biomarker for Diabetic Peripheral Neuropathy. Clin Ther 2021; 43:1457-1475. [PMID: 33965237 DOI: 10.1016/j.clinthera.2021.04.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/05/2021] [Accepted: 04/08/2021] [Indexed: 02/08/2023]
Abstract
PURPOSE Diagnosing early diabetic peripheral neuropathy remains a challenge due to deficiencies in currently advocated end points. The cornea is densely innervated with small sensory fibers, which are structurally and functionally comparable to intraepidermal nerve fibers. Corneal confocal microscopy is a method for rapid, noninvasive scanning of the living cornea with high resolution and magnification. METHODS This narrative review presents the framework for the development of biomarkers and the literature on the use and adoption of corneal confocal microscopy as an objective, diagnostic biomarker in experimental and clinical studies of diabetic peripheral neuropathy. A search was performed on PubMed and Google Scholar based on the terms "corneal confocal microscopy," "diabetic neuropathy," "corneal sensitivity," and "clinical trials." FINDINGS A substantial body of evidence underpins the thesis that corneal nerve loss predicts incident neuropathy and progresses with the severity of diabetic peripheral neuropathy. Corneal confocal microscopy also identifies early corneal nerve regeneration, strongly arguing for its inclusion as a surrogate end point in clinical trials of disease-modifying therapies. IMPLICATIONS There are sufficient diagnostic and prospective validation studies to fulfill the US Food and Drug Administration criteria for a biomarker to support the inclusion of corneal confocal microscopy as a primary end point in clinical trials of disease-modifying therapies in diabetic neuropathy.
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Affiliation(s)
| | | | - Maryam Ferdousi
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Shazli Azmi
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom; Centre for Diabetes, Endocrinology and Metabolism, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Alise Kalteniece
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Adnan Khan
- Research Division, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - Hoda Gad
- Research Division, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - Bilal Bashir
- Centre for Diabetes, Endocrinology and Metabolism, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Andrew Marshall
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom; Clinical Neurophysiology, The Walton Centre, Liverpool, United Kingdom; Division of Neuroscience and Experimental Psychology, Faculty of Medical and Human Sciences, University of Manchester, Manchester, United Kingdom
| | - Andrew J M Boulton
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom; Centre for Diabetes, Endocrinology and Metabolism, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Handrean Soran
- Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Rayaz A Malik
- Research Division, Weill Cornell Medicine-Qatar, Doha, Qatar; Faculty of Biology, Medicine and Health, University of Manchester, Cardiovascular Trials Unit, Manchester University NHS Foundation Trust, Manchester, United Kingdom.
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11
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Clarkson-Townsend DA, Douglass AJ, Singh A, Allen RS, Uwaifo IN, Pardue MT. Impacts of high fat diet on ocular outcomes in rodent models of visual disease. Exp Eye Res 2021; 204:108440. [PMID: 33444582 PMCID: PMC7946735 DOI: 10.1016/j.exer.2021.108440] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 12/23/2020] [Accepted: 01/05/2021] [Indexed: 02/08/2023]
Abstract
High fat diets (HFD) have been utilized in rodent models of visual disease for over 50 years to model the effects of lipids, metabolic dysfunction, and diet-induced obesity on vision and ocular health. HFD treatment can recapitulate the pathologies of some of the leading causes of blindness, such as age-related macular degeneration (AMD) and diabetic retinopathy (DR) in rodent models of visual disease. However, there are many important factors to consider when using and interpreting these models. To synthesize our current understanding of the importance of lipid signaling, metabolism, and inflammation in HFD-driven visual disease processes, we systematically review the use of HFD in mouse and rat models of visual disease. The resulting literature is grouped into three clusters: models that solely focus on HFD treatment, models of diabetes that utilize both HFD and streptozotocin (STZ), and models of AMD that utilize both HFD and genetic models and/or other exposures. Our findings show that HFD profoundly affects vision, retinal function, many different ocular tissues, and multiple cell types through a variety of mechanisms. We delineate how HFD affects the cornea, lens, uvea, vitreous humor, retina, retinal pigmented epithelium (RPE), and Bruch's membrane (BM). Furthermore, we highlight how HFD impairs several retinal cell types, including glia (microglia), retinal ganglion cells, bipolar cells, photoreceptors, and vascular support cells (endothelial cells and pericytes). However, there are a number of gaps, limitations, and biases in the current literature. We highlight these gaps and discuss experimental design to help guide future studies. Very little is known about how HFD impacts the lens, ciliary bodies, and specific neuronal populations, such as rods, cones, bipolar cells, amacrine cells, and retinal ganglion cells. Additionally, sex bias is an important limitation in the current literature, with few HFD studies utilizing female rodents. Future studies should use ingredient-matched control diets (IMCD), include both sexes in experiments to evaluate sex-specific outcomes, conduct longitudinal metabolic and visual measurements, and capture acute outcomes. In conclusion, HFD is a systemic exposure with profound systemic effects, and rodent models are invaluable in understanding the impacts on visual and ocular disease.
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Affiliation(s)
- Danielle A Clarkson-Townsend
- Gangarosa Department of Environmental Health, Emory University, Atlanta, GA, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA
| | - Amber J Douglass
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA
| | - Anayesha Singh
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Emory Center for Ethics, Emory University, Atlanta, GA, USA
| | - Rachael S Allen
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Ivie N Uwaifo
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Department of Neuroscience, Emory University, Atlanta, GA, USA
| | - Machelle T Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
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12
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Zhang WJ, Luo C, Pu FQ, Zhu JF, Zhu Z. The role and pharmacological characteristics of ATP-gated ionotropic receptor P2X in cancer pain. Pharmacol Res 2020; 161:105106. [DOI: 10.1016/j.phrs.2020.105106] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/21/2020] [Accepted: 07/24/2020] [Indexed: 02/07/2023]
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13
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Jiao H, Lim AS, Fazio Coles TE, McQuade RM, Furness JB, Chinnery HR. The effect of high-fat diet-induced metabolic disturbance on corneal neuroimmune features. Exp Eye Res 2020; 201:108298. [PMID: 33069696 DOI: 10.1016/j.exer.2020.108298] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 10/07/2020] [Accepted: 10/09/2020] [Indexed: 01/10/2023]
Abstract
PURPOSE The highly innervated cornea is susceptible to nerve loss secondary to systemic diseases such as diabetes and metabolic disturbances caused by high-fat diet. In this study, we characterize the effect of high-fat diet on the mouse corneal neuroimmune phenotype, including changes to corneal nerve density and resident immune cells, alongside the clinical assessment of corneal thickness and endothelial cell density. METHODS Male C57Bl6/J mice, aged 10 weeks, were fed a high-fat diet (60 kcal% fat, 5.2 kcal/g) or control diet (10 kcal%, 3.8 kcal/g) for 16 weeks. At the study endpoint, metabolic parameters (HbA1c, weight, fasting glucose, body fat) were measured to confirm metabolic disturbance. Clinical imaging of the anterior segment was performed using optical coherence tomography to measure the corneal epithelial and stromal thickness. Corneal sensory nerves were visualized using flatmount immunostaining and confocal microscopy. The topographical distribution and density of sensory nerves (BIII-tubulin+), intraepithelial CD45+ and MHC- II+ cells, stromal macrophages (IBA1+CD206+) and endothelial cells (ZO-1+) were analysed using FIJI. RESULTS High-fat diet mice had significantly higher blood HbA1c, higher body weight, a higher percentage of body fat and elevated fasting glucose compared to the control diet mice. Corneal epithelial and stromal thickness was similar in both groups. The sum length of the basal nerve plexus was lower in the central and peripheral cornea of mice fed a high-fat diet. In contrast, the sum length of superficial nerve terminals was similar between groups. Epithelial immune cell density was two-fold higher in the central corneas of high-fat diet mice compared to control diet mice. IBA1+CD206+ macrophage density was similar in the anterior stroma of both groups but was significantly higher in the posterior stroma of the peripheral cornea in the high-fat diet mice compared to controls. The percentage of nerve-associated MHC-II+ cells in the epithelium and stroma was higher in HFD mice compared to controls. Endothelial cell density was similar in the corneas of high-fat diet mice compared to controls. CONCLUSION Together with corneal neuropathy, corneal immune cells in mice fed a high-fat diet were differentially affected depending on their topographical distribution and location within cornea, and appeared in closer proximity to epithelial and stromal nerves, suggesting a local neuroimmune disruption induced by systemic metabolic disturbance.
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Affiliation(s)
- Haihan Jiao
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Alicia Sl Lim
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Therese E Fazio Coles
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia
| | - Rachel M McQuade
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; Department of Medicine, Western Health, Melbourne University, Sunshine, Victoria, Australia
| | - John B Furness
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Holly R Chinnery
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, Victoria, Australia.
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14
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Wang J, Calvert AE, Kaplan N, McMahon KM, Yang W, Lu KQ, Peng H, Thaxton CS, Lavker RM. HDL nanoparticles have wound healing and anti-inflammatory properties and can topically deliver miRNAs. ADVANCED THERAPEUTICS 2020; 3. [PMID: 33709017 DOI: 10.1002/adtp.202000138] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
microRNAs regulate numerous biological processes, making them potential therapeutic agents. Problems with delivery and stability of these molecules have limited their usefulness as treatments. We demonstrate that synthetic high-density lipoprotein nanoparticles (HDL NPs) topically applied to the intact ocular surface are taken up by epithelial and stromal cells. microRNAs complexed to HDL NPs (miR-HDL NPs) are similarly taken up by cells and tissues and retain biological activity. Topical treatment of diabetic mice with either HDL NPs or miR-HDL NPs significantly improved corneal re-epithelialization following wounding compared with controls. Mouse corneas with alkali burn-induced inflammation, topically treated with HDL NPs, displayed clinical, morphological and immunological improvement. These results should yield a novel HDL NP-based eye drop for patients with compromised wound healing ability (diabetics) and/or corneal inflammatory diseases (e.g. dry eye).
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Affiliation(s)
- Junyi Wang
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL.,Department of Ophthalmology, The Third Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Andrea E Calvert
- Department of Urology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Nihal Kaplan
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Kaylin M McMahon
- Department of Urology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Wending Yang
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Kurt Q Lu
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Han Peng
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - C Shad Thaxton
- Department of Urology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Robert M Lavker
- Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL
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15
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Lu X, Vick S, Chen Z, Chen J, Watsky MA. Effects of Vitamin D Receptor Knockout and Vitamin D Deficiency on Corneal Epithelial Wound Healing and Nerve Density in Diabetic Mice. Diabetes 2020; 69:1042-1051. [PMID: 32139594 PMCID: PMC7171964 DOI: 10.2337/db19-1051] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 02/23/2020] [Indexed: 12/20/2022]
Abstract
Diabetic keratopathy occurs in ∼70% of all people with diabetes. This study was designed to examine the effects of vitamin D receptor knockout (VDR-/-) and vitamin D deficiency (VDD) on corneal epithelial wound healing and nerve density in diabetic mice. Diabetes was induced using the low-dose streptozotocin method. Corneal epithelial wounds were created using an Algerbrush, and wound healing was monitored over time. Corneal nerve density was measured in unwounded mice. VDR-/- and VDD diabetic mice (diabetic for 8 and 20 weeks, respectively) had slower healing ratios than wild-type diabetic mice. VDR-/- and VDD diabetic mice also showed significantly decreased nerve density. Reduced wound healing ratios and nerve densities were not fully rescued by a supplemental diet rich in calcium, lactose, and phosphate. We conclude that VDR-/- and VDD significantly reduce both corneal epithelial wound healing and nerve density in diabetic mice. Because the supplemental diet did not rescue wound healing or nerve density, these effects are likely not specifically related to hypocalcemia. This work supports the hypothesis that low vitamin D levels can exacerbate preexisting ophthalmic conditions, such as diabetes.
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Affiliation(s)
- Xiaowen Lu
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA
| | - Sarah Vick
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA
| | - Zhong Chen
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA
| | - Jie Chen
- Biostatistics and Data Science, Department of Population Health Sciences, Medical College of Georgia, Augusta University, Augusta, GA
| | - Mitchell A Watsky
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA
- The Graduate School, Augusta University, Augusta, GA
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16
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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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17
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Marfurt C, Anokwute MC, Fetcko K, Mahony-Perez E, Farooq H, Ross E, Baumanis MM, Weinberg RL, McCarron ME, Mankowski JL. Comparative Anatomy of the Mammalian Corneal Subbasal Nerve Plexus. Invest Ophthalmol Vis Sci 2019; 60:4972-4984. [PMID: 31790560 PMCID: PMC6886725 DOI: 10.1167/iovs.19-28519] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 10/24/2019] [Indexed: 12/20/2022] Open
Abstract
Purpose The subbasal nerve plexus (SNP) is the densest and most recognizable component of the mammalian corneal innervation; however, the anatomical configuration of the SNP in most animal models remains incompletely described. The purpose of the current study is to describe in detail the SNP architecture in eight different mammals, including several popular animal models used in cornea research. Methods Corneal nerves in mouse, rat, guinea pig, rabbit, dog, macaque, domestic pig, and cow eyes were stained immunohistochemically with antiserum directed against neurotubulin. SNP architecture was documented by digital photomicrography and large-scale reconstructions, that is, corneal nerve maps, using a drawing tube attached to a light microscope. Results Subbasal nerve fibers (SNFs) in mice, rats, guinea pigs, dogs, and macaques radiated centrally from the corneoscleral limbus toward the corneal apex in a whorl-like or spiraling pattern. SNFs in rabbit and bovine corneas swept horizontally across the ocular surface in a temporal-to-nasal direction and converged on the inferonasal limbus without forming a spiral. SNFs in the pig cornea radiated centrifugally in all directions, like a starburst, from a focal point located equidistant between the corneal apex and the superior pole. Conclusions The results of the present study have demonstrated for the first time substantial interspecies differences in the architectural organization of the mammalian SNP. The physiological significance of these different patterns and the mechanisms that regulate SNP pattern formation in the mammalian cornea remain incompletely understood and warrant additional investigation.
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Affiliation(s)
- Carl Marfurt
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Miracle C. Anokwute
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Kaleigh Fetcko
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Erin Mahony-Perez
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Hassan Farooq
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Emily Ross
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Maraya M. Baumanis
- Indiana University School of Medicine-Northwest-Gary, Gary, Indiana, United States
| | - Rachel L. Weinberg
- Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Megan E. McCarron
- Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Joseph L. Mankowski
- Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
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18
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Calbiague VM, Vielma AH, Cadiz B, Paquet‐Durand F, Schmachtenberg O. Physiological assessment of high glucose neurotoxicity in mouse and rat retinal explants. J Comp Neurol 2019; 528:989-1002. [DOI: 10.1002/cne.24805] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 09/09/2019] [Accepted: 10/20/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Víctor M. Calbiague
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias Universidad de Valparaíso Valparaíso Chile
- Programa Doctorado en Ciencias, mención Neurociencias Universidad de Valparaíso Valparaíso Chile
| | - Alex H. Vielma
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias Universidad de Valparaíso Valparaíso Chile
| | - Bárbara Cadiz
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias Universidad de Valparaíso Valparaíso Chile
| | - Francois Paquet‐Durand
- Cell Death Mechanism Group Institute for Ophthalmic Research, University of Tübingen Tübingen Germany
| | - Oliver Schmachtenberg
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Facultad de Ciencias Universidad de Valparaíso Valparaíso Chile
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19
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Lipotoxicity reduces β cell survival through islet stellate cell activation regulated by lipid metabolism-related molecules. Exp Cell Res 2019; 380:1-8. [DOI: 10.1016/j.yexcr.2019.04.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/22/2019] [Accepted: 04/10/2019] [Indexed: 12/17/2022]
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20
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Pavlou S, Augustine J, Cunning R, Harkin K, Stitt AW, Xu H, Chen M. Attenuating Diabetic Vascular and Neuronal Defects by Targeting P2rx7. Int J Mol Sci 2019; 20:ijms20092101. [PMID: 31035433 PMCID: PMC6540042 DOI: 10.3390/ijms20092101] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 04/23/2019] [Accepted: 04/25/2019] [Indexed: 02/06/2023] Open
Abstract
Retinal vascular and neuronal degeneration are established pathological features of diabetic retinopathy. Data suggest that defects in the neuroglial network precede the clinically recognisable vascular lesions in the retina. Therefore, new treatments that target early-onset neurodegeneration would be expected to have great value in preventing the early stages of diabetic retinopathy. Here, we show that the nucleoside reverse transcriptase inhibitor lamivudine (3TC), a newly discovered P2rx7 inhibitor, can attenuate progression of both neuronal and vascular pathology in diabetic retinopathy. We found that the expression of P2rx7 was increased in the murine retina as early as one month following diabetes induction. Compared to non-diabetic controls, diabetic mice treated with 3TC were protected against the formation of acellular capillaries in the retina. This occurred concomitantly with a maintenance in neuroglial function, as shown by improved a- and b-wave amplitude, as well as oscillatory potentials. An improvement in the number of GABAergic amacrine cells and the synaptophysin-positive area was also observed in the inner retina of 3TC-treated diabetic mice. Our data suggest that 3TC has therapeutic potential since it can target both neuronal and vascular defects caused by diabetes.
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Affiliation(s)
- Sofia Pavlou
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK.
| | - Josy Augustine
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK.
| | - Rónán Cunning
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK.
| | - Kevin Harkin
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK.
| | - Alan W Stitt
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK.
| | - Heping Xu
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK.
| | - Mei Chen
- Centre for Experimental Medicine, School of Medicine, Dentistry & Biomedical Science, Queen's University Belfast, Belfast BT9 7BL, Northern Ireland, UK.
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21
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Lee Y, Kim MT, Rhodes G, Sack K, Son SJ, Rich CB, Kolachalama VB, Gabel CV, Trinkaus-Randall V. Sustained Ca2+ mobilizations: A quantitative approach to predict their importance in cell-cell communication and wound healing. PLoS One 2019; 14:e0213422. [PMID: 31017899 PMCID: PMC6481807 DOI: 10.1371/journal.pone.0213422] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 04/11/2019] [Indexed: 01/12/2023] Open
Abstract
Epithelial wound healing requires the coordination of cells to migrate as a unit over the basement membrane after injury. To understand the process of this coordinated movement, it is critical to study the dynamics of cell-cell communication. We developed a method to characterize the injury-induced sustained Ca2+ mobilizations that travel between cells for periods of time up to several hours. These events of communication are concentrated along the wound edge and are reduced in cells further away from the wound. Our goal was to delineate the role and contribution of these sustained mobilizations and using MATLAB analyses, we determined the probability of cell-cell communication events in both in vitro models and ex vivo organ culture models. We demonstrated that the injury response was complex and represented the activation of a number of receptors. In addition, we found that pannexin channels mediated the cell-cell communication and motility. Furthermore, the sustained Ca2+ mobilizations are associated with changes in cell morphology and motility during wound healing. The results demonstrate that both purinoreceptors and pannexins regulate the sustained Ca2+ mobilization necessary for cell-cell communication in wound healing.
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Affiliation(s)
- Yoonjoo Lee
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Min Tae Kim
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Garrett Rhodes
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Kelsey Sack
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, United States of America
| | - Sung Jun Son
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Celeste B. Rich
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Vijaya B. Kolachalama
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Christopher V. Gabel
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Vickery Trinkaus-Randall
- Department of Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts, United States of America
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22
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Bu Y, Shih KC, Kwok SS, Chan YK, Lo ACY, Chan TCY, Jhanji V, Tong L. Experimental modeling of cornea wound healing in diabetes: clinical applications and beyond. BMJ Open Diabetes Res Care 2019; 7:e000779. [PMID: 31803484 PMCID: PMC6887488 DOI: 10.1136/bmjdrc-2019-000779] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/06/2019] [Accepted: 11/03/2019] [Indexed: 12/11/2022] Open
Abstract
Diabetes mellitus is the most common cause of blindness in working age populations worldwide. While much of the focus for public health has been on secondary prevention in sight-threatening diabetic retinopathy, the cornea, including its epithelium and nerves, represents a major site of damage by chronic hyperglycemia. On injury, the diabetic cornea exhibits a delayed wound-healing response, as well as an altered ocular surface immune response. This suggests a potential association between the dysfunctional wound healing response and altered inflammation on the ocular surface. However, the presence of potential confounders makes this association difficult to investigate in human epidemiological studies. Thus, we turn to animal diabetic models for a better understanding. In this review, 20 original studies, published between 2008 and 2018, describe in vivo and in vitro models of diabetic cornea disease. We compared different models of diabetic cornea wound healing and discussed the relative strengths and drawbacks of each model. A number of molecular and cellular components involved in the corneal wound healing response that are altered in the presence of diabetes have been identified in the reviewed studies. Particularly, altered corneal epithelial protein concentrations of lumician and occludin were detected in diabetic eyes compared with controls. Additionally, the importance of IL-1β in modulating the inflammatory response after corneal injury in patients with diabetes and controls was further elucidated. Meanwhile, abnormal P2×7 receptor localization and decreased corneal sub-basal nerve density in diabetic eyes were shown to contribute to altered corneal nerve signaling after injury and thus affecting the wound healing response. Finally, the discovery of the therapeutic effects of topically administered aloe vera, Serpine 1, Resolvin D1 (RvD1), pigment epithelium-derived factor (PEDF) and Pro-His-Ser-Arg-Asn in diabetic animal models of cornea epithelial and nerve injury provide encouraging evidence for the future availability of effective treatment for diabetic keratopathy.
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Affiliation(s)
- Yashan Bu
- Department of Ophthalmology, University of Hong Kong, Hong Kong
| | | | - Sum Sum Kwok
- Department of Ophthalmology, University of Hong Kong, Hong Kong
| | - Yau Kei Chan
- Department of Ophthalmology, University of Hong Kong, Hong Kong
| | | | | | - Vishal Jhanji
- Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Louis Tong
- Department of Ophthalmology, Singapore National Eye Centre, Singapore
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23
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Freire D, Reyes RE, Baghram A, Davies DL, Asatryan L. P2X7 Receptor Antagonist A804598 Inhibits Inflammation in Brain and Liver in C57BL/6J Mice Exposed to Chronic Ethanol and High Fat Diet. J Neuroimmune Pharmacol 2018; 14:263-277. [PMID: 30353422 DOI: 10.1007/s11481-018-9816-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 10/09/2018] [Indexed: 02/06/2023]
Abstract
Chronic low-grade neuroinflammation is increasingly implicated in organ damage caused by alcohol abuse. Purinergic P2X7 receptors (P2X7Rs) play an important role in the generation of inflammatory responses during a number of CNS pathologies as evidenced from studies using pharmacological inhibition approach. P2X7Rs antagonism has not been tested during chronic alcohol abuse. In the present study, we tested the potential of P2X7R antagonist A804598 to reduce/abolish alcohol-induced neuroinflammation using chronic intragastric ethanol infusion and high-fat diet (Hybrid) in C57BL/6J mice. We have previously demonstrated an increase in neuroinflammatory response in 8 weeks of Hybrid paradigm. In the present study, we found neuroinflammatory response to 4 weeks of Hybrid exposure. A804598 treatment reversed the changes in microglia and astrocytes, reduced/abolished increases in mRNA levels of number of inflammatory markers, including IL-1β, iNOS, CXCR2, and components of inflammatory signaling pathways, such as TLR2, CASP1, NF-kB1 and CREB1, as well in the protein levels of pro-IL-1β and Nf-kB1. The P2X7R antagonist did not affect the increase in mRNA levels of fraktalkine (CX3CL1) and its receptor CX3CR1, an interaction that plays a neuroprotective role in neuron-glia communication. P2X7R antagonism also resulted in reduction of the inflammatory markers but did not alter steatosis in the liver. Taken together, these findings demonstrate how P2X7R antagonism suppresses inflammatory response in brain and liver but does not alter the neuroprotective response caused by Hybrid exposure. Overall, these findings support an important role of P2X7Rs in inflammation in brain and liver caused by combined chronic alcohol and high-fat diet. Graphical Abstract ᅟ.
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Affiliation(s)
- Daniel Freire
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90033, USA.,Department of Neurology, Keck School of Medicine, HCT 1520 San Pablo St, Los Angeles, CA, 90033, USA
| | - Rachel E Reyes
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90033, USA
| | - Ared Baghram
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90033, USA
| | - Daryl L Davies
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90033, USA
| | - Liana Asatryan
- Titus Family Department of Clinical Pharmacy, School of Pharmacy, University of Southern California, 1985 Zonal Avenue, Los Angeles, CA, 90033, USA.
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