1
|
Peng M, Rayana NP, Dai J, Sugali CK, Baidouri H, Suresh A, Raghunathan VK, Mao W. Cross-linked actin networks (CLANs) affect stiffness and/or actin dynamics in transgenic transformed and primary human trabecular meshwork cells. Exp Eye Res 2022; 220:109097. [PMID: 35569518 PMCID: PMC11029344 DOI: 10.1016/j.exer.2022.109097] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 04/20/2022] [Accepted: 04/25/2022] [Indexed: 01/14/2023]
Abstract
Cross-linked actin networks (CLANs) in trabecular meshwork (TM) cells may contribute to increased IOP by altering TM cell function and stiffness. However, there is a lack of direct evidence. Here, we developed transformed TM cells that form spontaneous fluorescently labelled CLANs. The stable cells were constructed by transducing transformed glaucomatous TM (GTM3) cells with the pLenti-LifeAct-EGFP-BlastR lentiviral vector and selection with blasticidin. The stiffness of the GTM3-LifeAct-GFP cells were studied using atomic force microscopy. Elastic moduli of CLANs in primary human TM cells treated with/without dexamethasone/TGFβ2 were also measured to validate findings in GTM3-LifeAct-GFP cells. Live-cell imaging was performed on GTM3-LifeAct-GFP cells treated with 1 μM latrunculin B or pHrodo bioparticles to determine actin stability and phagocytosis, respectively. The GTM3-LifeAct-GFP cells formed spontaneous CLANs without the induction of TGFβ2 or dexamethasone. The CLAN containing cells showed elevated cell stiffness, resistance to latrunculin B-induced actin depolymerization, as well as compromised phagocytosis, compared to the cells without CLANs. Primary human TM cells with dexamethasone or TGFβ2-induced CLANs were also stiffer and less phagocytic. The GTM3-LifeAct-GFP cells are a novel tool for studying the mechanobiology and pathology of CLANs in the TM. Initial characterization of these cells showed that CLANs contribute to at least some glaucomatous phenotypes of TM cells.
Collapse
Affiliation(s)
- Michael Peng
- Department of Ophthalmology, Eugene & Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Naga Pradeep Rayana
- Department of Ophthalmology, Eugene & Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jiannong Dai
- Department of Ophthalmology, Eugene & Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Chenna Kesavulu Sugali
- Department of Ophthalmology, Eugene & Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Hasna Baidouri
- Department of Basic Sciences, College of Optometry, University of Houston, Houston, TX, USA
| | - Ayush Suresh
- Department of Basic Sciences, College of Optometry, University of Houston, Houston, TX, USA; St. John's School, Houston, TX, USA
| | - Vijay Krishna Raghunathan
- Department of Basic Sciences, College of Optometry, University of Houston, Houston, TX, USA; Department of Biomedical Engineering, Cullen College of Engineering, University of Houston, Houston, TX, USA
| | - Weiming Mao
- Department of Ophthalmology, Eugene & Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, USA.
| |
Collapse
|
2
|
Mills JA, Liu F, Jarrett TR, Fletcher NL, Thurecht KJ. Nanoparticle based medicines: approaches for evading and manipulating the mononuclear phagocyte system and potential for clinical translation. Biomater Sci 2022; 10:3029-3053. [PMID: 35419582 DOI: 10.1039/d2bm00181k] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
For decades, nanomedicines have been reported as a potential means to overcome the limitations of conventional drug delivery systems by reducing side effects, toxicity and the non-ideal pharmacokinetic behaviour typically exhibited by small molecule drugs. However, upon administration many nanoparticles prompt induction of host inflammatory responses due to recognition and uptake by macrophages, eliminating up to 95% of the administered dose. While significant advances in nanoparticle engineering and consequent therapeutic efficacy have been made, it is becoming clear that nanoparticle recognition by the mononuclear phagocyte system (MPS) poses an impassable junction in the current framework of nanoparticle development. Hence, this has negative consequences on the clinical translation of nanotechnology with respect to therapeutic efficacy, systemic toxicity and economic benefit. In order to improve the translation of nanomedicines from bench-to-bedside, there is a requirement to either modify nanomedicines in terms of how they interact with intrinsic processes in the body, or modulate the body to be more accommodating for nanomedicine treatments. Here we provide an overview of the current standard for design elements of nanoparticles, as well as factors to consider when producing nanomedicines that have minimal MPS-nanoparticle interactions; we explore this landscape across the cellular to tissue and organ levels. Further, rather than designing materials to suit the body, a growing research niche involves modulating biological responses to administered nanomaterials. We here discuss how developing strategic methods of MPS 'pre-conditioning' with small molecule or biological drugs, as well as implementing strategic dosing regimens, such as 'decoy' nanoparticles, is essential to increasing nanoparticle therapeutic efficacy. By adopting such a perspective, we hope to highlight the increasing trends in research dedicated to improving nanomedicine translation, and subsequently making a positive clinical impact.
Collapse
Affiliation(s)
- Jessica A Mills
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia. .,Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072, Australia.,ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Australia
| | - Feifei Liu
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia. .,Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072, Australia.,ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Australia.,ARC Centre for Innovation in Biomedical Imaging Technology, Australia
| | - Thomas R Jarrett
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia. .,Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072, Australia.,ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Australia.,ARC Centre for Innovation in Biomedical Imaging Technology, Australia
| | - Nicholas L Fletcher
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia. .,Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072, Australia.,ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Australia
| | - Kristofer J Thurecht
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia. .,Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072, Australia.,ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Australia.,ARC Centre for Innovation in Biomedical Imaging Technology, Australia
| |
Collapse
|
3
|
Sgambellone S, Lucarini L, Lanzi C, Masini E. Novel Insight of Histamine and Its Receptor Ligands in Glaucoma and Retina Neuroprotection. Biomolecules 2021; 11:1186. [PMID: 34439851 PMCID: PMC8392511 DOI: 10.3390/biom11081186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/06/2021] [Accepted: 08/09/2021] [Indexed: 01/01/2023] Open
Abstract
Glaucoma is a multifactorial neuropathy characterized by increased intraocular pressure (IOP), and it is the second leading cause of blindness worldwide after cataracts. Glaucoma combines a group of optic neuropathies characterized by the progressive degeneration of retinal ganglionic cells (RGCs). Increased IOP and short-term IOP fluctuation are two of the most critical risk factors in glaucoma progression. Histamine is a well-characterized neuromodulator that follows a circadian rhythm, regulates IOP and modulates retinal circuits and vision. This review summarizes findings from animal models on the role of histamine and its receptors in the eye, focusing on the effects of histamine H3 receptor antagonists for the future treatment of glaucomatous patients.
Collapse
Affiliation(s)
- Silvia Sgambellone
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Pharmacology and Toxicology Section, University of Florence, 50139 Florence, Italy; (S.S.); (E.M.)
| | - Laura Lucarini
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Pharmacology and Toxicology Section, University of Florence, 50139 Florence, Italy; (S.S.); (E.M.)
| | - Cecilia Lanzi
- Toxicology Unit, Emergency Department, Careggi University Hospital, 50139 Florence, Italy;
| | - Emanuela Masini
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Pharmacology and Toxicology Section, University of Florence, 50139 Florence, Italy; (S.S.); (E.M.)
| |
Collapse
|
4
|
Konopińska J, Młynarczyk M, Dmuchowska DA, Obuchowska I. Posterior Capsule Opacification: A Review of Experimental Studies. J Clin Med 2021; 10:jcm10132847. [PMID: 34199147 PMCID: PMC8269180 DOI: 10.3390/jcm10132847] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 06/13/2021] [Accepted: 06/24/2021] [Indexed: 11/16/2022] Open
Abstract
Posterior capsule opacification (PCO) is the most common complication of cataract surgery. It causes a gradual deterioration of visual acuity, which would otherwise improve after a successful procedure. Despite recent advances in ophthalmology, this complication has not been eradicated, and the incidence of PCO can be as high as 10%. This article reviews the literature concerning the pathomechanism of PCO and examines the biochemical pathways involved in its formation and methods to prevent this complication. We also review the reported tests performed in cell cultures under laboratory conditions and in experimental animal models and in ex vivo human lens capsules. Finally, we describe research involving human eyes in the clinical setting and pharmacological methods that may reduce the frequency of PCO. Due to the multifactorial etiology of PCO, in vitro studies make it possible to assess the factors contributing to its complications and search for new therapeutic targets. Not all pathways involved in cell proliferation, migration, and contraction of the lens capsule are reproducible in laboratory conditions; moreover, PCO in humans and laboratory animals may be additionally stimulated by various degrees of postoperative reactions depending on the course of surgery. Therefore, further studies are necessary.
Collapse
|
5
|
Kim HJ, Lim SH. Clinical outcomes of trabecular microbypass stent (iStent) implantation in medically controlled open-angle glaucoma in the Korean population. Medicine (Baltimore) 2020; 99:e21729. [PMID: 32872056 PMCID: PMC7437814 DOI: 10.1097/md.0000000000021729] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
To evaluate the safety and efficacy [intraocular pressure (IOP)-lowering effect and medication use] of a single trabecular microbypass stent (iStent; Glaukos Corp, San Clemente, CA) for medically controlled open-angle glaucoma.This retrospective case series included 42 eyes of 34 patients with medically controlled open-angle glaucoma with IOP less than 21 mm Hg. Clinical outcomes analyzed were IOP, medication use, corrected distance visual acuity (CDVA), and surgical complications. Surgical success was defined according to 4 criteria: IOP < 21 mm Hg without medication; IOP < 18 mm Hg without medication; IOP < 15 mm Hg without medications; and IOP < 18 mm Hg with or without medication. Patients were followed for a minimum of 6 months postoperatively.Mean IOP was reduced from 15.8 ± 2.8 mm Hg to 14.5 ± 2.8 mm Hg (P < .001), while mean number of medications decreased from 2.2 ± 1.2 to 0.8 ± 1.1 at final visit (P < .001). Surgical success rates were 78.6%, 61.9%, 57.1%, and 97.6% at 6 months and 78.6%, 59.5%, 52.4%, and 95.2% at final visits according to criteria A, B, C, and D. Meanwhile, 59.5% of patients were medication-free at their final visit. The relative risk of surgical failure by Criteria B and C was 4.337 (95% confidence interval: 1.799-10.454) and 3.717 (95% confidence interval: 1.516-9.116) times greater in the higher-medication group (3 or more preoperative medications), respectively. CDVA was significantly improved from 0.41 ± 0.10 to 0.09 ± 0.07 LogMAR in the combined phacoemulsification and iStent implantation group (P < .001). There was no case whose vision was threatened (vision loss of 2 or more lines) or who showed severe complications after surgery.Single trabecular microbypass stent implantation was effective in reducing IOP and medication usage in patients with open-angle glaucoma with a low preoperative IOP. Our results imply that it is more difficult to achieve low target IOP control in eyes with higher numbers of preoperative medications.
Collapse
Affiliation(s)
- Hee Jun Kim
- Good Doctors Eye Hospital, Ulsan
- Department of Ophthalmology, Yeungnam University College of Medicine, Daegu
| | - Su-Ho Lim
- Department of Ophthalmology, Yeungnam University College of Medicine, Daegu
- Department of Ophthalmology, Daegu Veterans Health Service Medical Center, Daegu, Republic of Korea
| |
Collapse
|
6
|
Kaufman PL. Deconstructing aqueous humor outflow - The last 50 years. Exp Eye Res 2020; 197:108105. [PMID: 32590004 PMCID: PMC7990028 DOI: 10.1016/j.exer.2020.108105] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/29/2020] [Accepted: 06/02/2020] [Indexed: 12/27/2022]
Abstract
Herein partially summarizes one scientist-clinician's wanderings through the jungles of primate aqueous humor outflow over the past ~45 years. Totally removing the iris has no effect on outflow facility or its response to pilocarpine, whereas disinserting the ciliary muscle (CM) from the scleral spur/trabecular meshwork (TM) completely abolishes pilocarpine's effect. Epinephrine increases facility in CM disinserted eyes. Cytochalasins and latrunculins increase outflow facility, subthreshold doses of cytochalasins and epinephrine given together increase facility, and phalloidin, which has no effect on facility, partially blocks the effect of both cytochalasins and epinephrine. H-7, ML7, Y27632 and nitric oxide - donating compounds all increase facility, consistent with a mechanosensitive TM/SC. Adenosine A1 agonists increase and angiotensin II decrease facility. OCT and optical imaging techniques now permit visualization and digital recording of the distal outflow pathways in real time. Prostaglandin (PG) F2α analogues increase the synthesis and release of matrix metalloproteinases by the CM cells, causing remodeling and thinning of the interbundle extracellular matrix (ECM), thereby increasing uveoscleral outflow and reducing IOP. Combination molecules (one molecule, two or more effects) and fixed combination products (two molecules in one bottle) simplify drug regimens for patients. Gene and stem cell therapies to enhance aqueous outflow have been successful in laboratory models and may fill an unmet need in terms of patient compliance, taking the patient out of the delivery system. Functional transfer of genes inhibiting the rho cascade or decoupling actin from myosin increase facility, while genes preferentially expressed in the glaucomatous TM decrease facility. In live NHP, reporter genes are expressed for 2+ years in the TM after a single intracameral injection, with no adverse reaction. However, except for one recent report, injection of facility-effective genes in monkey organ cultured anterior segments (MOCAS) have no effect in live NHP. While intracameral injection of an FIV. BOVPGFS-myc.GFP PGF synthase vector construct reproducibly induces an ~2 mmHg reduction in IOP, the effect is much less than that of topical PGF2⍺ analogue eyedrops, and dissipates after 5 months. The turnoff mechanism has yet to be defeated, although proteasome inhibition enhances reporter gene expression in MOCAS. Intracanalicular injection might minimize off-target effects that activate turn-off mechanisms. An AD-P21 vector injected sub-tenon is effective in 'right-timing' wound healing after trabeculectomy in live laser-induced glaucomatous monkeys. In human (H)OCAS, depletion of TM cells by saponification eliminates the aqueous flow response to pressure elevation, which can be restored by either cultured TM cells or by IPSC-derived TM cells. There were many other steps along the way, but much was accomplished, biologically and therapeutically over the past half century of research and development focused on one very small but complex ocular apparatus. I am deeply grateful for this award, named for a giant in our field that none of us can live up to.
Collapse
Affiliation(s)
- Paul L Kaufman
- University of Wisconsin - Madison, School of Medicine & Public Health, Dept of Ophthalmology & Visual Sciences, United States.
| |
Collapse
|
7
|
Luparello C, Mauro M, Lazzara V, Vazzana M. Collective Locomotion of Human Cells, Wound Healing and Their Control by Extracts and Isolated Compounds from Marine Invertebrates. Molecules 2020; 25:E2471. [PMID: 32466475 PMCID: PMC7321354 DOI: 10.3390/molecules25112471] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 05/22/2020] [Accepted: 05/25/2020] [Indexed: 02/06/2023] Open
Abstract
The collective migration of cells is a complex integrated process that represents a common theme joining morphogenesis, tissue regeneration, and tumor biology. It is known that a remarkable amount of secondary metabolites produced by aquatic invertebrates displays active pharmacological properties against a variety of diseases. The aim of this review is to pick up selected studies that report the extraction and identification of crude extracts or isolated compounds that exert a modulatory effect on collective cell locomotion and/or skin tissue reconstitution and recapitulate the molecular, biochemical, and/or physiological aspects, where available, which are associated to the substances under examination, grouping the producing species according to their taxonomic hierarchy. Taken all of the collected data into account, marine invertebrates emerge as a still poorly-exploited valuable resource of natural products that may significantly improve the process of skin regeneration and restrain tumor cell migration, as documented by in vitro and in vivo studies. Therefore, the identification of the most promising invertebrate-derived extracts/molecules for the utilization as new targets for biomedical translation merits further and more detailed investigations.
Collapse
Affiliation(s)
- Claudio Luparello
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (STEBICEF), University of Palermo, 90128 Palermo, Italy; (M.M.); (V.L.); (M.V.)
| | | | | | | |
Collapse
|
8
|
Thomasy SM, Raghunathan VK, Miyagi H, Evashenk AT, Sermeno JC, Tripp GK, Morgan JT, Murphy CJ. Latrunculin B and substratum stiffness regulate corneal fibroblast to myofibroblast transformation. Exp Eye Res 2018; 170:101-107. [PMID: 29421383 DOI: 10.1016/j.exer.2018.02.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 01/11/2018] [Accepted: 02/05/2018] [Indexed: 10/18/2022]
Abstract
The transformation of keratocytes and fibroblasts to myofibroblasts is important to corneal wound healing as well as formation of stromal haze. The purpose of this study was to determine the effect of latrunculin B, an actin cytoskeleton disruptor in conjunction with a fundamental biophysical cue, substrate stiffness, on myofibroblast transformation in vitro and in vivo. Rabbit corneal fibroblasts were cultured on substrates of differing compliance (1.5, 22, and 71 kPa) and tissue culture plastic (TCP; > 1 GPa) in media containing 0 or 10 ng/ml TGFβ1 for 72 h. Cells were treated with 0.4 μM Lat-B or DMSO for 30 min every 24 h for 72 h. RNA was collected from cells and expression of alpha-smooth muscle actin (α-SMA), keratocan, and ALDH1A1 determined using qPCR; immunocytochemistry was used to assess α-SMA protein expression. A rabbit phototherapeutic keratectomy (PTK) model was used to assess the impact of 0.1% Lat-B (n = 3) or 25% DMSO (vehicle control, n = 3) on corneal wound healing by assessment of epithelial wound size with fluorescein stain and semi-quantitative stromal haze scoring by an observer masked to treatment group as well as Fourier-domain optical coherence tomography (FD-OCT) at set time points. Statistical analysis was completed using one-way or two-way analysis of variance. Treatment with Lat-B versus DMSO resulted in significantly less αSMA mRNA (P ≤ 0.007) for RCF cells grown on 22 and 71 kPa substrates as well as TCP without or with TGFβ1, and significantly decreased α-SMA protein expression in RCFs cultured on the intermediate (22 kPa) stiffness in the absence (P = 0.028) or presence (P = 0.018) of TGFβ1. Treatment with Lat-B versus DMSO but did not significantly alter expression of keratocan or ALDH1A1 mRNA in RCFs (P > 0.05) in the absence or presence of TGFβ1, but RCFs grown on stiff hydrogels (71 kPa) had significantly more keratocan mRNA expression versus the 22 kPa hydrogel or TCP (P < 0.001) without TGFβ1. Administration of topical Lat-B BID was well tolerated by rabbits post-PTK but did not significantly alter epithelial wound closure, stromal haze score, stromal haze thickness as measured by FD-OCT in comparison to DMSO-treated rabbits. When corneal stromal cells are cultured on substrates possessing biologically relevant substratum stiffnesses, Lat-B modulates mRNA and protein expression of α-SMA and thus modulates myofibroblast transformation. At a dose and dose-frequency that reduced IOP in human glaucoma patients, Lat-B treatment did not substantially impact corneal epithelial or stromal wound healing in a rabbit PTK model. While a significant impact on wound healing was observed at the concentration and dose frequency reported here was not found, encouraging in vitro data support further investigations of topically applied Lat-B to determine if this compound can reduce stromal fibrosis.
Collapse
Affiliation(s)
- Sara M Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA; Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, Davis, CA, USA.
| | - Vijay Krishna Raghunathan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA; Department of Basic Sciences, The Ocular Surface Institute, College of Optometry, University of Houston, Houston, TX, USA
| | - Hidetaka Miyagi
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA; Department of Ophthalmology and Visual Sciences, Graduate School of Biomedical Sciences, Hiroshima University, Minami-ku, Kasumi 1-2-3, Hiroshima, 7348551, Japan
| | - Alexander T Evashenk
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - Jasmyne C Sermeno
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - Geneva K Tripp
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - Joshua T Morgan
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - Christopher J Murphy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA; Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, Davis, CA, USA
| |
Collapse
|
9
|
Efficacy of Topically Administered Rho-Kinase Inhibitor AR-12286 in Patients With Exfoliation Syndrome and Ocular Hypertension or Glaucoma. J Glaucoma 2017; 25:e807-14. [PMID: 27552517 DOI: 10.1097/ijg.0000000000000508] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
PURPOSE To evaluate the efficacy of rho-associated protein kinase inhibitor, AR-12286 topical solution, for its effect in eyes with exfoliation syndrome (XFS) and ocular hypertension (OHT) or exfoliative glaucoma (XFG) and examine any lasting effect on intraocular pressure (IOP) after discontinuation. METHODS Prospective, double-masked, randomized, interventional study. Patients with XFS and OHT or XFG were enrolled. The study eyes were treated once daily with AR-12286, randomized to 0.5% or 0.7% for 24 weeks. Visits included baseline, 1, 4, and 12 weeks after drug initiation; at 12 weeks AR-12286 was discontinued for 1 week and was resumed at week 13. At the week 24 visit, AR-12286 was discontinued, and a final reexamination was performed at week 25. RESULTS Ten patients were treated. Mean baseline IOP was 25±2.4 mm Hg, mean IOP was reduced to 19.1±2.3 mm Hg at 1 week (P<0.001), 17.5±3.6 mm Hg at 4 weeks (P<0.001), and 17.4±3.6 mm Hg at 12 weeks (P<0.001), yielding an average IOP reduction of 23.6%, 30%, and 30.4%, respectively. At the week 13 visit, 1 week after the drug was discontinued, mean IOP increased to 21.6±5.4 mm Hg (P=0.06 compared with baseline visit). At week 24, the mean IOP was 21.8±7.8 mm Hg (P=0.2, and AR-12286 was discontinued). At week 25, the mean IOP was 21.3±5.3 mm Hg (P=0.06). CONCLUSIONS AR-12286 was well tolerated and provided statistically significant reduction in IOP in patients with XFS and OHT or XFG. This drug may represent an additional therapeutic paradigm for the treatment of XFG.
Collapse
|
10
|
O'Callaghan J, Cassidy PS, Humphries P. Open-angle glaucoma: therapeutically targeting the extracellular matrix of the conventional outflow pathway. Expert Opin Ther Targets 2017; 21:1037-1050. [PMID: 28952395 DOI: 10.1080/14728222.2017.1386174] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
INTRODUCTION Ocular hypertension in open-angle glaucoma is caused by a reduced rate of removal of aqueous humour (AH) from the eye, with the majority of AH draining from the anterior chamber through the conventional outflow pathway, comprising the trabecular meshwork (TM) and Schlemm's Canal. Resistance to outflow is generated, in part, by the extracellular matrix (ECM) of the outflow tissues. Current pressure-lowering topical medications largely suppress AH production, or enhance its clearance through the unconventional pathway. However, therapies targeting the ECM of the conventional pathway in order to decrease intraocular pressure have become a recent focus of attention. Areas covered: We discuss the role of ECM of the TM in outflow homeostasis and its relevance as a target for glaucoma therapy, including progress in development of topical eye formulations, together with gene therapy approaches based on inducible, virally-mediated expression of matrix metalloproteinases to enhance aqueous outflow. Expert opinion: There remains a need for improved glaucoma medications that more specifically act upon sites causative to glaucoma pathogenesis. Emerging strategies targeting the ECM of the conventional outflow pathway, or associated components of the cytoskeleton of TM cells, involving new pharmacological formulations or genetically-based therapies, are promising avenues of future glaucoma treatment.
Collapse
Affiliation(s)
- Jeffrey O'Callaghan
- a Ocular Genetics Unit, Smurfit Institute of Genetics , University of Dublin, Trinity College , Dublin , Ireland
| | - Paul S Cassidy
- a Ocular Genetics Unit, Smurfit Institute of Genetics , University of Dublin, Trinity College , Dublin , Ireland
| | - Pete Humphries
- a Ocular Genetics Unit, Smurfit Institute of Genetics , University of Dublin, Trinity College , Dublin , Ireland
| |
Collapse
|
11
|
Andrés-Guerrero V, García-Feijoo J, Konstas AG. Targeting Schlemm's Canal in the Medical Therapy of Glaucoma: Current and Future Considerations. Adv Ther 2017; 34:1049-1069. [PMID: 28349508 PMCID: PMC5427152 DOI: 10.1007/s12325-017-0513-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Indexed: 11/23/2022]
Abstract
Schlemm’s canal (SC) is a unique, complex vascular structure responsible for maintaining fluid homeostasis within the anterior segment of the eye by draining the excess of aqueous humour. In glaucoma, a heterogeneous group of eye disorders afflicting approximately 60 million individuals worldwide, the normal outflow of aqueous humour into SC is progressively hindered, leading to a gradual increase in outflow resistance, which gradually results in elevated intraocular pressure (IOP). By and large available antiglaucoma therapies do not target the site of the pathology (SC), but rather aim to decrease IOP by other mechanisms, either reducing aqueous production or by diverting aqueous flow through the unconventional outflow system. The present review first outlines our current understanding on the functional anatomy of SC. It then summarizes existing research on SC cell properties; first in the context of their role in glaucoma development/progression and then as a target of novel and emerging antiglaucoma therapies. Evidence from ongoing research efforts to develop effective antiglaucoma therapies targeting SC suggests that this could become a promising site of future therapeutic interventions.
Collapse
|
12
|
Ko MK, Kim EK, Gonzalez JM, Tan JC. Dose- and time-dependent effects of actomyosin inhibition on live mouse outflow resistance and aqueous drainage tissues. Sci Rep 2016; 6:21492. [PMID: 26884319 PMCID: PMC4756686 DOI: 10.1038/srep21492] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 01/26/2016] [Indexed: 11/13/2022] Open
Abstract
Actomyosin contractility modulates outflow resistance of the aqueous drainage tissues and intraocular pressure, a key pathogenic factor of glaucoma. We established methodology to reliably analyze the effect of latrunculin-B (Lat-B)-induced actin depolymerization on outflow physiology in live mice. A voltage-controlled microperfusion system for delivering drugs and simultaneously analyzing outflow resistance was tested in live C57BL/6 mice. Flow rate and perfusion pressure were reproducible within a coefficient of variation of 2%. Outflow facility for phosphate-buffered saline (0.0027 ± 0.00036 μL/min/mmHg; mean ± SD) and 0.02% ethanol perfusions (Lat-B vehicle; 0.0023 ± 0.0005 μL/min/mmHg) were similar and stable over 2 hours (p > 0.1 for change), indicating absence of a ‘washout’ artifact seen in larger mammals. Outflow resistance changed in graded fashion, decreasing dose- and time-dependently over 2 hours for Lat-B doses of 2.5 μM (p = 0.29), 5 μM (p = 0.039) and 10 μM (p = 0.001). Resulting outflow resistance was about 10 times lower with 10 μM Lat-B than vehicle control. The filamentous actin network was decreased and structurally altered in the ciliary muscle (46 ± 5.6%) and trabecular meshwork (37 ± 8.3%) of treated eyes relative to vehicle controls (p < 0.005; 5 μM Lat-B). Mouse actomyosin contractile mechanisms are important to modulating aqueous outflow resistance, mirroring mechanisms in primates. We describe approaches to reliably probe these mechanisms in vivo.
Collapse
Affiliation(s)
- MinHee K Ko
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Eun Kyoung Kim
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Jose M Gonzalez
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - James C Tan
- Doheny Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| |
Collapse
|
13
|
Rasmussen CA, Kaufman PL. Exciting directions in glaucoma. Can J Ophthalmol 2015; 49:534-43. [PMID: 25433744 DOI: 10.1016/j.jcjo.2014.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 08/13/2014] [Indexed: 01/15/2023]
Abstract
Glaucoma is a complex, life-long disease that requires an individualized, multifaceted approach to treatment. Most patients will be started on topical ocular hypotensive eyedrop therapy, and over time multiple classes of drugs will be needed to control their intraocular pressure. The search for drugs with novel mechanisms of action, to treat those who do not achieve adequate intraocular pressure control with, or become refractory to, current therapeutics, is ongoing, as is the search for more efficient, targeted drug delivery methods. Gene-transfer and stem-cell applications for glaucoma therapeutics are moving forward. Advances in imaging technologies improve our understanding of glaucoma pathophysiology and enable more refined patient evaluation and monitoring, improving patient outcomes.
Collapse
Affiliation(s)
- Carol A Rasmussen
- Department of Ophthalmology & Visual Sciences, School of Medicine & Public Health, University of Wisconsin-Madison, Madison, WI, USA..
| | - Paul L Kaufman
- Department of Ophthalmology & Visual Sciences, School of Medicine & Public Health, University of Wisconsin-Madison, Madison, WI, USA
| |
Collapse
|
14
|
Rasmussen CA, Kaufman PL, Ritch R, Haque R, Brazzell RK, Vittitow JL. Latrunculin B Reduces Intraocular Pressure in Human Ocular Hypertension and Primary Open-Angle Glaucoma. Transl Vis Sci Technol 2014; 3:1. [PMID: 25237590 DOI: 10.1167/tvst.3.5.1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2014] [Accepted: 06/17/2014] [Indexed: 01/09/2023] Open
Abstract
PURPOSE To evaluate the safety, tolerability, and intraocular pressure (IOP)-lowering effect of Latrunculin-B (Lat-B), a marine macrolide that disrupts the actin cytoskeleton, in patients with ocular hypertension (OHT) or early primary open-angle glaucoma (POAG). METHODS In this Phase I, multicenter, double-masked, randomized, placebo-controlled, ascending-dose study, subjects with bilateral OHT or early POAG (>22 mm Hg) received one of four concentrations of INS115644 (Lat-B ophthalmic solutions, 0.005%, 0.01%, 0.02%, or 0.05%) in one eye over 3 days (5 single-dose instillations, separated by 12 hours). One eye was randomly assigned to active drug, the other to placebo. IOP was measured prior to treatment initiation (day 0) and on days 1 and 3. RESULTS Baseline IOPs were 22.9 ± 2.4 mm Hg and 23.5 + 3.1 mm Hg in the 0.02% and 0.05% dose groups, respectively. At 4 hours post instillation of the first dose, 0.02% INS115644 reduced IOP from baseline (mean ± SE) by 3.8 ± 0.7 mm Hg (P = 0.002) and 0.05% by 3.9 ± 1.0 mm Hg (P = 0.004). A maximum IOP decrease of 24% was noted at 4 hours after the fifth instillation of 0.02%. Adjusting for diurnal baseline and IOP in the contralateral, placebo-treated eye, the maximal 12-hour hypotensive effect was 4.0 ± 0.5 mm Hg (adjusted mean ± SE), a 17% decrease, following the fifth instillation of 0.02% (day 3). Adverse events were few and consisted mainly of mild redness, irritation, and a transient, clinically insignificant increase (≤2.5%) in central corneal thickness. CONCLUSIONS In OHT or POAG patients, twice daily Lat-B significantly lowered IOP compared with contralateral, placebo-treated eyes, with few and mild ocular adverse events. TRANSLATIONAL RELEVANCE Lat-B may be a potential therapeutic agent for glaucoma.
Collapse
Affiliation(s)
- Carol A Rasmussen
- Department of Ophthalmology, University of Wisconsin, Madison, Wisconsin
| | - Paul L Kaufman
- Department of Ophthalmology, University of Wisconsin, Madison, Wisconsin
| | - Robert Ritch
- Einhorn Clinical Research Center, New York Eye and Ear Infirmary at Mount Sinai School of Medicine, New York, New York
| | - Reza Haque
- Inspire Pharmaceuticals, Durham, North Carolina
| | | | | |
Collapse
|
15
|
Zhang Z, Dhaliwal AS, Tseng H, Kim JD, Schuman JS, Weinreb RN, Loewen NA. Outflow tract ablation using a conditionally cytotoxic feline immunodeficiency viral vector. Invest Ophthalmol Vis Sci 2014; 55:935-40. [PMID: 24448264 DOI: 10.1167/iovs.13-12890] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To create an in vivo model of vector-mediated trabecular meshwork (TM) ablation and replacement. METHODS We generated a conditionally cytotoxic, trackable vector, HSVtkiG, that expressed herpes simplex virus 1 thymidine kinase (HSVtk) and enhanced green fluorescent protein (eGFP). We optimized HSVtkiG ablation in vitro with ganciclovir (GCV) in comparison to eGFP control vector GINSIN and investigated the mechanism. Right eyes of 24 rats were then injected intracamerally with either HSVtkiG or GINSIN, before intraperitoneal GCV was administered 1 week later. Intraocular pressure, central corneal thickness (CCT), and slit-lamp exams were assessed for 8 weeks. Transduction and ablation were followed by gonioscopic visualization of eGFP. Histology was obtained with TM cell counts and immunohistochemistry markers of inflammation. RESULTS Transduction and ablation parameters were established in vitro. Apoptosis was the cause of cell death. In vivo, transduction was seen gonioscopically to be targeted to the TM, followed by disappearance of eGFP marker fluorescence in HSVtkiG-transduced cells after injection of GCV. Ablation resulted in an IOP decrease of 25% in HSVtkiG-injected eyes 2 days after GCV but not in GINSIN or noninjected control eyes (P < 0.05). Trabecular meshwork cellularity was decreased at the time of lowest IOP and recovered thereafter, while CCT remained unchanged. Inflammation was absent. CONCLUSIONS A vector-based system for inducible ablation of cells of the outflow tract was developed. Trabecular meshwork ablation lowered IOP, and recovery of cellularity and IOP followed. This model may be useful to study pressure regulation by the TM, its stem cells, and migration patterns.
Collapse
Affiliation(s)
- Ze Zhang
- Yale University School of Medicine, New Haven, Connecticut
| | | | | | | | | | | | | |
Collapse
|
16
|
Gong H, Yang CYC. Morphological and hydrodynamic correlations with increasing outflow facility by rho-kinase inhibitor Y-27632. J Ocul Pharmacol Ther 2014; 30:143-53. [PMID: 24460021 DOI: 10.1089/jop.2013.0192] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Abstract Rho-kinase inhibitors affect actomyosin cytoskeletal networks and have been shown to significantly increase outflow facility and lower intraocular pressure in various animal models and human eyes. This article summarizes common morphological changes in the trabecular meshwork induced by Rho-kinase inhibitors and specifically compares the morphological and hydrodynamic correlations with increased outflow facility by Rho-kinase inhibitor, Y-27632, in bovine, monkey, and human eyes under similar experimental conditions. Interspecies comparison has shown that morphological changes in the juxtacanalicular connective tissue (JCT) of these 3 species were different. However, these different morphological changes in the JCT, no matter if it's separation between the JCT and inner wall in bovine eyes, or separation between the JCT cells or between the JCT cells and their matrix in monkey eyes, or even no separation between the inner wall and the JCT but a more subtle expansion of the JCT in human eyes, appear to correlate with the increased percent change of outflow facility. More importantly, these different morphological changes all resulted in an increase in effective filtration area, which was positively correlated with increased outflow facility in all 3 species. These results suggest a link among changes in outflow facility, tissue architecture, and aqueous outflow pattern. Y-27632 increases outflow facility by redistributing aqueous outflow through a looser and larger area in the JCT.
Collapse
Affiliation(s)
- Haiyan Gong
- 1 Department of Ophthalmology, Boston University School of Medicine , Boston, Massachusetts
| | | |
Collapse
|
17
|
Medical Management of Exfoliative Glaucoma. Clin Ophthalmol 2014; 54:57-70. [DOI: 10.1097/iio.0000000000000043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
18
|
Inoue T, Tanihara H. Rho-associated kinase inhibitors: A novel glaucoma therapy. Prog Retin Eye Res 2013; 37:1-12. [DOI: 10.1016/j.preteyeres.2013.05.002] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 05/12/2013] [Accepted: 05/29/2013] [Indexed: 01/15/2023]
|
19
|
Yang CYC, Liu Y, Lu Z, Ren R, Gong H. Effects of Y27632 on aqueous humor outflow facility with changes in hydrodynamic pattern and morphology in human eyes. Invest Ophthalmol Vis Sci 2013; 54:5859-70. [PMID: 23920374 DOI: 10.1167/iovs.12-10930] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
PURPOSE To determine the effect of Y27632, a Rho-kinase inhibitor on aqueous outflow facility, flow pattern, and juxtacanalicular tissue (JCT)/trabecular meshwork (TM) morphology in human eyes. METHODS Sixteen enucleated human eyes were perfused with PBS plus glucose (GPBS) at 15 mm Hg to establish the baseline outflow facility. Six eyes were perfused for short-duration (30 minute) with either 50 μM Y27632 or GPBS (n = 3 per group). Ten eyes were perfused for long duration (3 hours) with either 50 μM Y27632 or GPBS (n = 5 per group). Outflow pattern was labeled using fluorescent microspheres, and effective filtration length (EFL) was measured. Morphologic changes and their relationship to EFL and facility were analyzed. RESULTS Outflow facility significantly increased after short-duration perfusion with Y27632 compared with its own baseline (P = 0.03), but did not reach statistical significance compared with its controls (P = 0.07). Outflow facility (P = 0.01) and EFL (P < 0.05) were significantly increased after long-duration perfusion with Y27632 compared with its controls. Increases in outflow facility and EFL demonstrated a positive correlation. Morphologically, the TM and JCT of high-tracer regions were more expanded compared with low-tracer regions. A significant increase in JCT thickness was found in the long-duration Y27632 group compared with its control group (10.0 vs. 8.0 μm, P < 0.01). CONCLUSIONS Y27632 increases outflow facility in human eyes. This increase correlates positively with an increase in EFL, which is associated with an increased expansion in the JCT. Our data suggest that EFL could serve as a novel parameter to correlate with outflow facility.
Collapse
Affiliation(s)
- Chen-Yuan Charlie Yang
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts 02118, USA
| | | | | | | | | |
Collapse
|
20
|
Torrejon KY, Pu D, Bergkvist M, Danias J, Sharfstein ST, Xie Y. Recreating a human trabecular meshwork outflow system on microfabricated porous structures. Biotechnol Bioeng 2013; 110:3205-18. [PMID: 23775275 DOI: 10.1002/bit.24977] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Revised: 06/04/2013] [Accepted: 06/07/2013] [Indexed: 01/15/2023]
Abstract
Glaucoma is the leading cause of irreversible blindness, resulting from an increase in intraocular pressure (IOP). IOP is the only modifiable risk factor of glaucoma and is controlled by the outflow of the aqueous humor through the human trabecular meshwork (HTM). Currently, the lack of a proper in vitro HTM model impedes advances in understanding outflow physiology and discovering effective IOP-lowering anti-glaucoma therapeutics. Therefore, we designed and constructed an in vitro HTM model using micropatterned, porous SU-8 scaffolds, which support cells to recapitulate functional HTM morphology and allow the study of outflow physiology. The pore size of SU-8 scaffolds, surface coating, cell seeding density, and culture duration were evaluated for HTM cell growth. The bioengineered HTM was characterized by F-actin staining and immunocytochemistry of HTM markers. A stand-alone perfusion chamber with an integrated pressure sensing system was further constructed and used for the investigation of the outflow facility of the bioengineered HTM treated with latrunculin B-an IOP lowering agent. Cells in the in vitro model exhibited HTM-like morphology, expression of α-smooth muscle actin, myocilin, and αß-crystallin, outflow characteristics and drug responsiveness. Altogether, we have developed an in vitro HTM model system for understanding HTM cell biology and screening of pharmacological or biological agents that affect trabecular outflow facility, expediting discovery of IOP-lowering, anti-glaucoma therapeutics.
Collapse
Affiliation(s)
- Karen Y Torrejon
- College of Nanoscale Science and Engineering, University at Albany, State University of New York, 257 Fuller Road, Albany, New York, 12203
| | | | | | | | | | | |
Collapse
|
21
|
Clark R, Nosie A, Walker T, Faralli JA, Filla MS, Barrett-Wilt G, Peters DM. Comparative genomic and proteomic analysis of cytoskeletal changes in dexamethasone-treated trabecular meshwork cells. Mol Cell Proteomics 2012; 12:194-206. [PMID: 23105009 DOI: 10.1074/mcp.m112.019745] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Changes in the actin cytoskeleton, especially the formation of cross-linked actin networks (CLANs) are thought to contribute to the increased intraocular pressure observed in primary open-angle and steroid-induced glaucoma. To better understand the effects of glucocorticoids, we employed a shotgun method to analyze global changes in the cytoskeleton and integrin signaling pathways following dexamethasone (DEX) treatment of human trabecular meshwork (HTM) cells. RNA and cell lysates were obtained from HTM cells incubated with or without DEX. Changes in protein expression were determined by mass spectrometry (MS) following differential centrifugation of cell lysates to enrich for low-abundance cytoskeletal and signaling proteins, proteolytic digestion, and a titanium dioxide column to enrich for phosphopeptides. Results were validated by Western blots. Changes in RNA levels were determined with gene arrays and RT-PCR. Overall, MS identified 318 cytoskeleton associated proteins. Five of these proteins (PDLIM1, FGFR1OP, leiomodin-1, ZO-2 and LRP16A) were only detected in DEX-treated cells by MS. However, only PDLIM1 showed a statistically significant increase at the RNA level. Other proteins with differences at both the RNA and protein levels included β3 integrin, caveolin-1, Borg2, raftlin1, PI-3 kinase regulatory subunit α, transgelin, and filamin B. By immunofluorescence microscopy filamin B and PDLIM1 showed enhanced expression in human trabecular meshwork cells, but only PDLIM1 demonstrated significant localization within CLANs. Finally, MS showed that some of the cytoskeleton proteins (Borg2, leiomodin-1, LRP16A, raftlin1 and CKAP4) contained phosphorylated residues. This study suggests that DEX affects the expression of cytoskeleton proteins at the transcriptional and translational level and shows that a combined genomic and proteomic approach can be used for rapid analysis of proteins in the TM. It also shows that DEX altered the expression of components (PDLIM1 and β3 integrins) involved in CLAN formation and provides new findings into the effects of glucocorticoids on the cytoskeleton.
Collapse
Affiliation(s)
- Ross Clark
- Departments of Pathology and Laboratory Medicine, University of Wisconsin, Madison, Wisconsin 53706, USA
| | | | | | | | | | | | | |
Collapse
|
22
|
Tian B, Kaufman PL. Comparisons of actin filament disruptors and Rho kinase inhibitors as potential antiglaucoma medications. EXPERT REVIEW OF OPHTHALMOLOGY 2012; 7:177-187. [PMID: 22737177 PMCID: PMC3378243 DOI: 10.1586/eop.12.12] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Dynamics of the actin cytoskeleton in the trabecular meshwork play a crucial role in the regulation of trabecular outflow resistance. The actin filament disruptors and Rho kinase inhibitors affect the dynamics of the actomyosin system by either disrupting the actin filaments or inhibiting the Rho kinase-activated cellular contractility. Both approaches induce similar morphological changes and resistance decreases in the trabecular outflow pathway, and thus both have potential as antiglaucoma medications. Although the drugs might induce detrimental changes in the cornea following topical administration, lower drug concentrations in larger volumes as used clinically, but not higher drug concentrations in smaller volumes as used experimentally, could minimize corneal toxicity. Additionally, developments of trabecular meshwork-specific actin filament disruptors or Rho kinase inhibitors, prodrugs and new drug-delivery methods might avoid the drugs' toxicity to the cornea. Gene therapies with cytoskeleton-modulating proteins may mimic the effects of the cytoskeleton-modulating agents and have the potential to permanently decrease trabecular outflow resistance.
Collapse
Affiliation(s)
- Baohe Tian
- Department of Ophthalmology & Visual Sciences, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WI 53792, USA
| | - Paul L Kaufman
- Department of Ophthalmology & Visual Sciences, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WI 53792, USA
| |
Collapse
|
23
|
Vadlapudi AD, Patel A, Cholkar K, Mitra AK. Recent Patents on Emerging Therapeutics for the Treatment of Glaucoma, Age Related Macular Degeneration and Uveitis. RECENT PATENTS ON BIOMEDICAL ENGINEERING 2012; 5:83-101. [PMID: 25414810 PMCID: PMC4235159 DOI: 10.2174/1874764711205010083] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Advancements in the field and rising interest among pharmaceutical researchers have led to the development of new molecules with enhanced therapeutic activity. Design of new drugs which can target a particular pathway and/or explore novel targets is of immense interest to ocular pharmacologists worldwide. Delivery of suitable pharmacologically active agents at proper dose (within the therapeutic window) to the target tissues without any toxicity to the healthy ocular tissues still remain an elusive task. Moreover, the presence of static and dynamic barriers to drug absorption including the corneal epithelium (lipophilic), corneal and scleral stroma (hydrophilic), conjunctival lymphatics, choroidal vasculature and the blood-ocular barriers also pose a significant challenge for achieving therapeutic drug concentrations at the target site. Although many agents are currently available, new compounds are being introduced for treating various ocular diseases. Deeper understanding of the etiology and complex mechanisms associated with the disease condition would aid in the development of potential therapeutic candidates. Novel small molecules as well as complex biotechnology derived macromolecules with superior efficacy, safety and tolerability are being developed. Therefore, this review article provides an overview of existing drugs, treatment options, advances in emerging therapeutics and related recent patents for the treatment of ocular disorders such as glaucoma, age related macular degeneration (AMD) and uveitis.
Collapse
Affiliation(s)
- Aswani Dutt Vadlapudi
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108-2718, USA
| | - Ashaben Patel
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108-2718, USA
| | - Kishore Cholkar
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108-2718, USA
| | - Ashim K. Mitra
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 2464 Charlotte Street, Kansas City, MO 64108-2718, USA
| |
Collapse
|
24
|
Kutuzova GD, Gabelt BT, Kiland JA, Hennes-Beann EA, Kaufman PL, DeLuca HF. 1α,25-Dihydroxyvitamin D(3) and its analog, 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D(3) (2MD), suppress intraocular pressure in non-human primates. Arch Biochem Biophys 2011; 518:53-60. [PMID: 22198282 DOI: 10.1016/j.abb.2011.10.022] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 10/19/2011] [Accepted: 10/29/2011] [Indexed: 01/16/2023]
Abstract
Ocular hypertension is the greatest known risk factor for glaucoma that affects an estimated 70 million people worldwide. Lowering intraocular pressure (IOP) remains the mainstay of therapy in the management of glaucoma. By means of microarray analysis, we have discovered that 1α,25-dihydroxyvitamin D(3) (1α,25-(OH)(2)D(3)) regulates genes that are known to be involved in the determination of intraocular pressure (IOP). Topical administration of 1α,25-(OH)(2)D(3) or its analog, 2-methylene-19-nor-(20S)-1α,25-dihydroxyvitamin D(3) (2MD), markedly reduces IOP in non-human primates. The reduction in IOP is not the result of reduced aqueous humor formation, while a 35% increase in aqueous humor drainage by 1α,25-(OH)(2)D(3) was found but this increase did not achieve significance. Nevertheless, our results suggest that 1α,25-(OH)(2)D(3), or an analog thereof, may present a new approach to the treatment of glaucoma.
Collapse
Affiliation(s)
- Galina D Kutuzova
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706-1544, United States
| | | | | | | | | | | |
Collapse
|
25
|
Cytoskeletal drugs prevent posterior capsular opacification in human lens capsule in vitro. Graefes Arch Clin Exp Ophthalmol 2011; 250:507-14. [PMID: 22138731 DOI: 10.1007/s00417-011-1869-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Revised: 11/09/2011] [Accepted: 11/15/2011] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND To determine whether the cytoskeletal drugs H-7 and Latrunculin B (LAT-B) inhibit posterior capsular opacification (PCO) in the cultured human lens capsular bag. METHODS Following extracapsular cataract (lens) extraction in human donor eyes, the capsular bag was prepared and cultured by standard techniques. Forty-eight capsular bags were studied, of which 13 were treated with H-7 (50, 100 or 300 μM), 12 with 1% BSS (vehicle of H-7), 11 with LAT-B (2, 5 or 10 μM), and 12 with 0.25% DMSO (vehicle of LAT-B). Forty out of the 48 capsular bags were from paired eyes of 20 donors, with one bag being treated with H-7/LAT-B and the other with BSS/DMSO for each pair, including 20 for the H-7-BSS protocol and 20 for the LAT-B-DMSO protocol. The medium with the cytoskeletal drug/vehicle was replaced every 3-4 days for 4 weeks. PCO was assessed daily using inverted phase-contrast microscopy, and scored on a 4-point scale. RESULTS In all cultures with BSS or DMSO, residual lens epithelial cells (LECs) on the anterior capsule migrated to and proliferated on the posterior capsule by 3-7 days, and apparent LEC growth on the posterior capsule with severe capsular wrinkling (PCO Grade 3) was seen by 2-3 weeks. When treated continuously with H-7 or LAT-B, the migration and proliferation of LECs and the capsular wrinkling were inhibited in a dose-dependent manner, with the inhibition being complete (PCO Grade 0) in the 300 μM H-7 (n = 8, p < 0.001) or 10 μM LAT-B culture (n = 3, p = 0.002). CONCLUSION H-7 and LAT-B dose-dependently inhibited PCO formation in the cultured human lens capsular bags, suggesting that cytoskeletal drugs might prevent PCO formation after surgery in the human eye.
Collapse
|
26
|
Wood JA, McKee CT, Thomasy SM, Fischer ME, Shah NM, Murphy CJ, Russell P. Substratum compliance regulates human trabecular meshwork cell behaviors and response to latrunculin B. Invest Ophthalmol Vis Sci 2011; 52:9298-303. [PMID: 22064990 DOI: 10.1167/iovs.11-7857] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
PURPOSE To determine the impact of substratum compliance and latrunculin-B (Lat-B), both alone and together, on fundamental human trabecular meshwork (HTM) cell behavior. Lat-B is a reversible actin cytoskeleton disruptor that decreases resistance to aqueous humor outflow and decreases intraocular pressure. METHODS HTM cells were cultured on polyacrylamide hydrogels possessing values for compliance that mimic those reported for normal and glaucomatous HTM, or tissue culture plastic (TCP). Cells were treated with 0.2 μM or 2.0 μM Lat-B in dimethyl sulfoxide (DMSO) or DMSO alone. The impact of substratum compliance and/or Lat-B treatment on cell attachment, proliferation, surface area, aspect ratio, and migration were investigated. RESULTS HTM cells had profoundly decreased attachment and proliferation rates when cultured on hydrogels possessing compliance values that mimic those found for healthy HTM. The effect of Lat-B treatment on HTM cell surface area was less for cells cultured on more compliant hydrogels compared with TCP. HTM cell migration was increased on stiffer hydrogels that mimic the compliance of glaucomatous HTM and on TCP in comparison with more compliant hydrogels. Lat-B treatment decreased cellular migration on all surfaces for at least 7 hours after treatment. CONCLUSIONS Substratum compliance profoundly influenced HTM cell behaviors and modulated the response of HTM cells to Lat-B. The inclusion of substratum compliance that reflects healthy or glaucomatous HTM results in cell behaviors and responses to therapeutic agents in vitro that may more accurately reflect in vivo conditions.
Collapse
Affiliation(s)
- Joshua A Wood
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA 95616, USA
| | | | | | | | | | | | | |
Collapse
|
27
|
Lu Z, Zhang Y, Freddo TF, Gong H. Similar hydrodynamic and morphological changes in the aqueous humor outflow pathway after washout and Y27632 treatment in monkey eyes. Exp Eye Res 2011; 93:397-404. [PMID: 21669200 DOI: 10.1016/j.exer.2011.05.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Revised: 05/18/2011] [Accepted: 05/27/2011] [Indexed: 10/18/2022]
Abstract
Our previous studies in bovine eyes demonstrated that the structural correlate to the increase in outflow facility after either Rho-kinase inhibitor Y-27632 (Y27) treatment or washout appeared to be separation between the juxtacanalicular tissue (JCT) and inner wall (IW) of the aqueous plexus, the bovine equivalent of Schlemm's canal (SC). While these findings suggest that Y27 and washout may increase outflow facility through a similar mechanism, the anatomy of bovine outflow pathway differs considerably from both the human and monkey outflow pathway; however, only the human eye does not exhibit washout. In light of this, we compared the effects of Y27 and washout on outflow facility, hydrodynamic patterns of outflow, and the morphology of the IW and JCT in monkey eyes, given that their anatomy is closer to human eyes. Twelve freshly enucleated monkey eyes were used in this study. Eyes were perfused with Dulbecco's PBS containing 5.5 mM glucose (GPBS) to establish a baseline facility at 15 mmHg. Four eyes were perfused for a short-duration (30 min) as a control, 4 eyes for a long-duration (180 min) to induce washout, and 4 eyes with GPBS+50 μM Y27 for 30 min. All eyes were then perfused with fluorescent microspheres (0.5 μm; 0.002%) to label the hydrodynamic patterns of outflow and then perfusion-fixed. Confocal images of frontal sections were taken along the IW of SC. The total length (TL) and the tracer-decorated length (FL) of the IW were measured to calculate the average percent effective filtration length (PEFL = FL/TL). Sections with SC were examined by light and electron microscopy. The TL of the IW and the length exhibiting separation (SL) in the JCT were measured to calculate the average percent separation length (PSL = SL/TL). Outflow facility increased 149.2% (p < 0.01) from baseline after washout during long-duration perfusion, and 114.9% (p = 0.004) after Y27 treatment, but did not change significantly after short-duration perfusion in control eyes (p = 0.46). Distribution of the tracer labeling appeared punctate along the IW of control eyes, while a more uniform pattern was observed after washout and Y27 treatment. PEFL in washout (83.4 ± 2.1%) and Y27 treated eyes (82.5 ± 1.6%) was 3.4-fold larger compared to controls (24.2 ± 4.2%, P < 0.001). The JCT appeared distended with loss of connections between JCT cells and between JCT cells and their extracelluar matrix in eyes with washout or after Y-27 treatment. PSL in the JCT was 2.3-fold larger in washout eyes (77.4 ± 3.3%) and 2.2-fold larger in Y27 treated eyes (75.2 ± 5.3%) versus controls (33.5 ± 5.3%, p = 0.001). Significant positive correlations were found between outflow facility and PEFL, facility and PSL and between PEFL and PSL. Our data demonstrated that similar hydrodynamic and morphological changes occurred in the aqueous humor outflow pathway of monkey eyes after induction of washout and Y27 treatment. Both Y27 and washout increase outflow facility by redistributing aqueous outflow through a larger area in the JCT. These hydrodynamic changes are likely driven by morphologic changes associated with a decrease in cell-cell and cell-matrix connections in the JCT.
Collapse
Affiliation(s)
- Zhaozeng Lu
- Huashan Hospital of Fudan University, Shanghai, PR China
| | | | | | | |
Collapse
|
28
|
Chen J, Runyan SA, Robinson MR. Novel ocular antihypertensive compounds in clinical trials. Clin Ophthalmol 2011; 5:667-77. [PMID: 21629573 PMCID: PMC3104796 DOI: 10.2147/opth.s15971] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Indexed: 01/31/2023] Open
Abstract
Introduction: Glaucoma is a multifactorial disease characterized by progressive optic nerve injury and visual field defects. Elevated intraocular pressure (IOP) is the most widely recognized risk factor for the onset and progression of open-angle glaucoma, and IOP-lowering medications comprise the primary treatment strategy. IOP elevation in glaucoma is associated with diminished or obstructed aqueous humor outflow. Pharmacotherapy reduces IOP by suppressing aqueous inflow and/or increasing aqueous outflow. Purpose: This review focuses on novel non-FDA approved ocular antihypertensive compounds being investigated for IOP reduction in ocular hypertensive and glaucoma patients in active clinical trials within approximately the past 2 years. Methods: The mode of IOP reduction, pharmacology, efficacy, and safety of these new agents were assessed. Relevant drug efficacy and safety trials were identified from searches of various scientific literature databases and clinical trial registries. Compounds with no specified drug class, insufficient background information, reformulations, and fixed-combinations of marketed drugs were not considered. Results: The investigational agents identified comprise those that act on the same targets of established drug classes approved by the FDA (ie, prostaglandin analogs and β-adrenergic blockers) as well as agents belonging to novel drug classes with unique mechanisms of action. Novel targets and compounds evaluated in clinical trials include an actin polymerization inhibitor (ie, latrunculin), Rho-associated protein kinase inhibitors, adenosine receptor analogs, an angiotensin II type 1 receptor antagonist, cannabinoid receptor agonists, and a serotonin receptor antagonist. Conclusion: The clinical value of novel compounds for the treatment of glaucoma will depend ultimately on demonstrating favorable efficacy and benefit-to-risk ratios relative to currently approved prostaglandin analogs and β-blockers and/or having complementary modes of action.
Collapse
Affiliation(s)
- June Chen
- Department of Biological Sciences, Allergan, Inc., 2525 Dupont Dr., Irvine, CA 92612, USA.
| | | | | |
Collapse
|
29
|
The effect of biophysical attributes of the ocular trabecular meshwork associated with glaucoma on the cell response to therapeutic agents. Biomaterials 2011; 32:2417-23. [PMID: 21220171 DOI: 10.1016/j.biomaterials.2010.11.071] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Accepted: 11/30/2010] [Indexed: 11/22/2022]
Abstract
Glaucoma is a devastating neurodegenerative disease, which can lead to vision loss and is associated with irreversible damage to retinal ganglion cells. Although the mechanism of disease onset remains unknown, we have recently demonstrated that the stiffness of the ocular trabecular meshwork (HTM) increases dramatically in human donor eyes with a history of glaucoma. Here we report that polyacrylamide hydrogels, which mimic the compliant conditions of normal and glaucomatous HTM, profoundly modulate cytoskeletal dynamics and the elastic modulus of the overlying HTM cells. Substratum compliance also modulates HTM cell response to Latrunculin-B, a cytoskeletal disrupting agent currently in human clinical trials for the treatment of glaucoma. Additionally, we observed a compliance-dependent rebound effect of Latrunculin-B with an unexpected increase in HTM cell elastic modulus being observed upon withdrawal of the drug. The results predict that cytoskeletal disrupting drugs may be more potent in advanced stages of glaucoma.
Collapse
|
30
|
Gabelt BT, Kaufman PL, Rasmussen CA. Effect of nitric oxide compounds on monkey ciliary muscle in vitro. Exp Eye Res 2010; 93:321-7. [PMID: 21147103 DOI: 10.1016/j.exer.2010.12.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Revised: 11/21/2010] [Accepted: 12/06/2010] [Indexed: 01/22/2023]
Abstract
The effects of various nitric oxide compounds and their inhibitors on monkey ciliary muscle contraction in vitro were investigated in both the longitudinal and circular vectors. The responses to nitric oxide compounds in carbachol precontracted ciliary muscle consisted of an initial relaxation often followed by recovery to near carbachol precontracted levels while the compound was still present. Sodium nitroprusside produced the greatest relaxation responses (nearly 100% relaxation in both vectors at 10(-3) M). The highest concentrations of isosorbide dinitrate (10(-4) M) and L-arginine (10(-3) M) produced relaxation responses of approximately 50% in both vectors. 8-Bromo cyclic GMP produced the smallest relaxation responses (25-35%). Nitric oxide synthase inhibition enhanced carbachol contraction up to 20% in the longitudinal but not the circular vector. Phosphodiesterase inhibition did not further enhance the relaxation response to L-arginine. Guanylate cyclase inhibition partially attenuated the relaxation response to sodium nitroprusside. Nitric oxide generating compounds were effective in relaxing precontracted monkey ciliary muscle in vitro. Endogenous production of nitric oxide is likely involved in the regulation of the contractile response in monkey ciliary muscle. Nitric oxide generating compounds may have potential value in therapeutic areas where modulation of ciliary muscle tension is desirable.
Collapse
Affiliation(s)
- B'Ann T Gabelt
- Department of Ophthalmology & Visual Sciences, University of Wisconsin, 600 Highland Ave, Madison, WI 53792, United States.
| | | | | |
Collapse
|
31
|
Inoue T, Pattabiraman PP, Epstein DL, Vasantha Rao P. Effects of chemical inhibition of N-WASP, a critical regulator of actin polymerization on aqueous humor outflow through the conventional pathway. Exp Eye Res 2009; 90:360-7. [PMID: 19961849 DOI: 10.1016/j.exer.2009.11.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 10/09/2009] [Accepted: 11/25/2009] [Indexed: 11/17/2022]
Abstract
The integrity of actin cytoskeletal organization in aqueous humor outflow pathway is thought to play a critical role in modulation of aqueous humor outflow through the trabecular meshwork. Our understanding of the regulation of actin cytoskeletal dynamics in outflow pathway, however, is very limited. To explore the potential importance of Neural Wiskott-Aldrich syndrome protein (N-WASP), a critical regulator of actin polymerization/nucleation in aqueous humor outflow pathway, the effects of Wiskostatin, a selective pharmacological inhibitor of N-WASP, on aqueous humor outflow facility were evaluated using enucleated porcine eyes and a constant pressure perfusion system. Further, drug induced effects on actin cytoskeletal organization, cell adhesions, myosin II phosphorylation, matrix metalloproteinase (MMP) activity, and cytoskeletal protein profile in porcine trabecular meshwork (TM) cells were determined by immunofluorescence, zymography, and mass spectrometry. Aqueous humor outflow facility was increased significantly and progressively in the Wiskostatin perfused porcine eyes. The Wiskostatin perfused eyes appear to exhibit increased giant vacuoles in the inner wall of aqueous plexi and deformation of aqueous plexi. The Wiskostatin treated TM cells demonstrated extensive vacuoles in their cytosol, and both actin stress fibers and focal adhesions were decreased in a reversible manner. The drug-treated TM cells also revealed decreased myosin II and actin in the cytoskeletal enriched triton insoluble fraction but did not affect myosin II phosphorylation or MMP-2 activity. These data demonstrate that the chemical inhibition of N-WASP increases aqueous humor outflow facility in association with decreased actomyosin interaction and cell adhesive interactions revealing the importance of N-WASP in homeostasis of aqueous humor outflow.
Collapse
Affiliation(s)
- Toshihiro Inoue
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC 27710, USA
| | | | | | | |
Collapse
|
32
|
Angelilli A, Ritch R. Directed therapy for exfoliation syndrome. Open Ophthalmol J 2009; 3:70-4. [PMID: 19888433 PMCID: PMC2771265 DOI: 10.2174/1874364100903020070] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Revised: 03/28/2009] [Accepted: 04/02/2009] [Indexed: 11/22/2022] Open
Abstract
Exfoliation syndrome (XFS) is an age-related disorder of the extracellular matrix that leads the production of abnormal fibrillar material that leads to elevated intraocular pressure and a relatively severe glaucoma. Exfoliation material is deposited in numerous ocular tissues and extraocular organs. XFS is associated with ocular ischemia, cerebrovascular disease, neurodegenerative disease and cardiovascular disease. Current modalities of treatment include intraocular pressure lowering with topical antihypertensives, laser trabeculoplasty and filtration surgery. The disease paradigm for XFS should be expanded to include directed therapy designed specifically to target the underlying disease process. Potential targets include preventing the formation or promoting the depolymerization of exfoliation material. Novel therapies targeting trabecular meshwork may prove particularly useful in the care of exfoliative glaucoma. The systemic and ocular associations of XFS underscore the need for a comprehensive search for neuroprotective agents in its treatment.
Collapse
Affiliation(s)
- Allison Angelilli
- Einhorn Clinical Research Center, New York Eye and Ear Infirmary, New York, NY, USA
| | - Robert Ritch
- Einhorn Clinical Research Center, New York Eye and Ear Infirmary, New York, NY, USA
- Department of Ophthalmology, New York Medical College, Valhalla, NY, USA
| |
Collapse
|
33
|
Abstract
Exfoliation syndrome (XFS) is an age-related disorder of the extracellular matrix that leads the production of abnormal fibrillar material that leads to elevated intraocular pressure and a relatively severe glaucoma. Exfoliation material is deposited in numerous ocular tissues and extraocular organs. XFS is associated with ocular ischemia, cerebrovascular disease, neurodegenerative disease and cardiovascular disease. Current modalities of treatment include intraocular pressure lowering with topical antihypertensives, laser trabeculoplasty and filtration surgery. The disease paradigm for XFS should be expanded to include directed therapy designed specifically to target the underlying disease process. Potential targets include preventing the formation or promoting the depolymerization of exfoliation material. Novel therapies targeting trabecular meshwork may prove particularly useful in the care of exfoliative glaucoma. The systemic and ocular associations of XFS underscore the need for a comprehensive search for neuroprotective agents in its treatment.
Collapse
Affiliation(s)
- Allison Angelilli
- Einhorn Clinical Research Center, New York Eye and Ear Infirmary, New York, NY, USA
| | | |
Collapse
|
34
|
|
35
|
The role of the actomyosin system in regulating trabecular fluid outflow. Exp Eye Res 2008; 88:713-7. [PMID: 18793636 DOI: 10.1016/j.exer.2008.08.008] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 08/04/2008] [Accepted: 08/05/2008] [Indexed: 01/06/2023]
Abstract
Abnormally high resistance to aqueous humor drainage via the trabecular meshwork and Schlemm's canal is highly correlated with the development of primary open-angle glaucoma. Contractility of the actomyosin system in the trabecular cells or inner wall endothelium of Schlemm's canal is an important factor in the regulation of outflow resistance. Cytoskeletal agents, affecting F-actin integrity or actomyosin contractility, or gene therapies, employing overexpression of caldesmon or Rho-A inhibition, can decrease outflow resistance in the drainage pathway. In this review, we discuss the mechanisms underlying these and similar effects on trabecular outflow resistance in living animals and/or in cultured ocular anterior segments from enucleated animal or human eyes.
Collapse
|
36
|
Wang H, Liu X, Guo L, Gabelt BT, Lee PY, Podos SM, Wang N, Kaufman PL. Effects of MISA A on actin cytoskeleton of cultured HTM cells and intraocular pressure of rats and glaucomatous monkeys. Curr Eye Res 2008; 32:843-50. [PMID: 17963104 DOI: 10.1080/02713680701585880] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
PURPOSE To determine the effects of misakinolide (MISA) A, which leads to the disassembly of actin filaments, on the actin cytoskeleton of cultured human trabecular meshwork (HTM) cells and on intraocular pressure (IOP) in living rats and monkeys. METHODS Cultured HTM cells were treated with MISA A, and the changes in the actin cytoskeleton were determined by immunofluorescence microscopy. Elevated IOP was induced in cynomolgus monkeys by unilateral laser photocoagulation of the trabecular meshwork (TM). The IOP response after topical administration of MISA A was determined in normotensive rats (Tonopen) and glaucomatous monkeys (pneumotonometer and Tonopen) at 0.5, 1, 2, 3, 4, 5, and 6 hr. RESULTS MISA A caused dose- and time-dependent disruption of actin stress fibers in cultured HTM cells. Actin microfilaments and vinculin containing focal contacts deteriorated after 2 hr, 30 and 10 min of incubation with 5 nM, 10 nM, and 25 nM MISA A, respectively. Recovery was also dose- and time-dependent. The actin-disrupting effects were not reversible when the cells were incubated with MISA A at a low dose (10 nM) for 24 hr or a high dose (25 nM) for 30 min. Topical administration of MISA A significantly decreased IOP in rats by 5.8 +/- 0.5 (mean +/- SEM) (p < 0.05) Tonopen rat units. In monkeys, IOP was decreased by 3.8 +/- 0.5 mmHg (p < 0.001) in the normotensive eye and by 9.2 +/- 1.2 mmHg (p < 0.001) in the glaucomatous eye. CONCLUSIONS MISA A greatly altered the actin cytoskeleton and cellular adhesions and reduced IOP, suggesting that MISA A may be a useful antiglaucoma strategy.
Collapse
Affiliation(s)
- Haiyan Wang
- Tongren Ophthalmic Center, Beijing Tongren Hospital, Capital Medical University, Beijing, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Abstract
Exfoliation syndrome (XFS) is an age-related, generalized disorder of the extracellular matrix characterized by the production and progressive accumulation of a fibrillar extracellular material in many ocular tissues and is the most common identifiable cause of open-angle glaucoma worldwide. XFS plays an etiologic role in open-angle glaucoma, angle-closure glaucoma, cataract, and retinal vein occlusion. It is accompanied by an increase in serious complications at the time of cataract extraction, such as zonular dialysis, capsular rupture, and vitreous loss. It is associated systemically with an increasing number of vascular disorders, hearing loss, and Alzheimer's disease. XFS appears to be a disease of elastic tissue microfibrils. The characteristic fibrils, composed of microfibrillar subunits surrounded by an amorphous matrix comprising various glycoconjugates, contain predominantly epitopes of elastic fibers, such as elastin, tropoelastin, amyloid P, vitronectin, and components of elastic microfibrils, such as fibrillin-1, fibulin-2, vitronectin, microfibril-associated glycoprotein (MAGP-1), and latent TGF-beta binding proteins (LTBP-1 and LTBP-2), the proteoglycans syndecan and versican, the extracellular chaperone clusterin, the cross-linking enzyme lysyl oxidase, and other proteins. A recent milestone study showed that two common single nucleotide polymorphisms in the coding region of the lysyl oxidase-like 1 (LOXL1) gene located on chromosome 15 were specifically associated with XFS and XFG. LOXL1 is a member of the lysyl oxidase family of enzymes, which are essential for the formation, stabilization, maintenance, and remodeling of elastic fibers and prevent age-related loss of elasticity of tissues. LOXL1 protein is a major component of exfoliation deposits and appears to play a role in its accumulation and in concomitant elastotic processes in intra- and extraocular tissues of XFS patients. This discovery should open the way to new approaches and directions of therapy for this protein disorder.
Collapse
Affiliation(s)
- Robert Ritch
- New York Eye and Ear Infirmary, New York, New York 10003, USA.
| |
Collapse
|
38
|
Chapter 13 Outflow Signaling Mechanisms and New Therapeutic Strategies for the Control of Intraocular Pressure. CURRENT TOPICS IN MEMBRANES 2008. [DOI: 10.1016/s1063-5823(08)00413-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
39
|
Toris CB, Camras CB. Chapter 8 Aqueous Humor Dynamics II. CURRENT TOPICS IN MEMBRANES 2008. [DOI: 10.1016/s1063-5823(08)00408-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
40
|
The mechanism of increasing outflow facility by rho-kinase inhibition with Y-27632 in bovine eyes. Exp Eye Res 2007; 86:271-81. [PMID: 18155193 DOI: 10.1016/j.exer.2007.10.018] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Revised: 09/11/2007] [Accepted: 10/25/2007] [Indexed: 11/24/2022]
Abstract
Rho-kinase inhibitor Y-27632 (Y-27) affects actomyosin cytoskeletal networks and has been shown to significantly increase outflow facility (C) in enucleated porcine and rabbit eyes, as well as in vivo monkey eyes without obvious toxicity. The mechanisms underlying these responses remain largely unknown. In this study, we investigate how Y-27 affects aqueous humor C, the hydrodynamic patterns of outflow, and the morphology of the inner wall (IW) and juxtacanalicular connective tissue (JCT). 12 bovine eyes were perfused at 15 mmHg with Dulbecco's PBS containing 5.5 mM glucose (DPBS) to establish stable baseline C. The anterior chamber was exchanged and perfused with DPBS containing 50 microM Y-27 in 7 eyes, while 5 eyes received DPBS alone. Eyes were then perfused with DPBS containing fluorescent microspheres (0.5 microm; 0.002% v/v) at a fixed volume to deliver equivalent amounts of tracer to label the hydrodynamic filtration patterns. All eyes were perfusion-fixed with Karnovsky's fixative. Radial and frontal sections were prepared in all quadrants and confocal images were taken along the IW of the aqueous plexus (AP). The total length (TL) and filtration length (FL) of the IW were measured in > or =16 images/eye, and the average percent effective filtration length (PEFL=FL/TL) was calculated. Sections with AP were processed and examined by light and electron microscopy. The TL of the IW and length exhibiting JCT/IW separation (SL) were measured in > or =16 micrographs/eye, and the average percent separation length (PSL=SL/TL) was also calculated. After Y-27 treatment, C increased from 1.54+/-0.34 (+/-SEM) to 2.36+/-0.54 microL/min per mmHg (58.2+/-18.9%) while control eyes changed from 1.67+/-0.41 to 1.71+/-0.39 microl/min per mmHg (6.0+/-9.3%) and the percent changes between the Y-27-treated and control eyes were significant (p=0.03). Control eyes showed segmental distribution of tracer in the trabecular meshwork tending to cluster near collector channel ostia, whereas Y-27-treated eyes showed a more uniform pattern and extensive labeling along the IW. In Y-27-treated eyes, PEFL was 3-fold larger (57.6+/-3.7%) compared to control eyes (18.2+/-4.5%; p<0.001). Light microscopic examination revealed that, with Y-27, the IW and JCT were significantly distended compared to control eyes, with discernible separation between the IW and JCT. PSL was 2.8-fold larger in Y-27-treated eyes (59.3+/-3.6%) than in controls (20.8+/-2.0%; p<0.001). A significant positive correlation was found between PEFL and PSL (p=0.003) suggesting that as connectivity between the JCT and IW decreases the available area for aqueous humor drainage increases along the AP. Our study also demonstrates a significant positive correlation between C and the PSL (p=0.01), a finding identical to what we reported to occur during the "washout" effect in bovine eyes. Our data suggests the structural correlate to the increase in C and PEFL after Y-27-treatment is physical separation between the JCT and IW. The increase in C after Y-27-treatment may share a similar mechanism comparable with the washout effect that occurs in bovine eyes. Overall, these findings support our hypothesis that JCT/IW connectivity influences local outflow hydrodynamics that regulate C, and suggest that strategies targeting JCT/IW connectivity are promising anti-glaucoma therapies to reduce IOP.
Collapse
|
41
|
Kaufman PL. Enhancing trabecular outflow by disrupting the actin cytoskeleton, increasing uveoscleral outflow with prostaglandins, and understanding the pathophysiology of presbyopia interrogating Mother Nature: asking why, asking how, recognizing the signs, following the trail. Exp Eye Res 2007; 86:3-17. [PMID: 18053986 DOI: 10.1016/j.exer.2007.10.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2007] [Revised: 10/17/2007] [Accepted: 10/22/2007] [Indexed: 01/06/2023]
Abstract
Several major areas of work by the author and his international collaborators are reviewed. (1) The ciliary muscle in the non-human primate eye was disinserted at the scleral spur. Pilocarpine was then ineffective in increasing outflow facility, indicating that ciliary muscle contraction mediated the IOP-lowering effect of muscarinic cholinergics. (2) Compounds such as cytochalasins, H-7 and latrunculin A/B, which alter the actin cytoskeleton, cellular contractility and cellular adhesions in cultured trabecular meshwork cells, relaxed trabecular pathway cells and consequently the meshwork itself so as to decrease IOP and enhance trabecular outflow facility in non-human primates. Gene transfer approaches utilizing C3 and caldesmon over-expression by viral vectors to target specific steps in the cellular contractility/cytoskeleton/cell adhesion cascades characteristically altered trabecular meshwork cell morphology and increased outflow facility in organ-cultured anterior segments. (3) Prostaglandin F(2alpha) analogues enhanced matrix metalloproteinase production by ciliary muscle cells and scleral fibroblasts, leading to remodeling of the extracellular matrix of the ciliary muscle and sclera and consequently to increased uveoscleral outflow and decreased IOP in primates. (4) The rhesus monkey was an excellent model for human presbyopia, losing the accommodative response to cholinergic stimulation in the same timeframe relative to lifespan. No changes were found in ciliary muscle enzymes involved in acetylcholine biosynthesis or degradation or in muscarinic receptor numbers or affinity. Contractility of isolated ciliary muscle did not diminish with age, but posterior ciliary muscle attachments stiffened, suggesting a possible role in restricting muscle and consequently lens movement during accommodation. A model to reproducibly stimulate accommodation through central stimulation of the Edinger-Westphal nucleus was developed. Goniovideography and ultrasound biomicroscopic techniques allowed real-time recording and analysis of the accommodation-relevant structures. Surgical ablation of the intraocular structures involved in the accommodation response has led to further understanding of their roles and changes with age related to presbyopia. (5) Global collaborations such as those involved in these studies will be essential in the future, as science becomes "bigger".
Collapse
Affiliation(s)
- Paul L Kaufman
- University of Wisconsin, School of Medicine and Public Health, Ophthalmology & Visual Sciences, 2870 University Ave, Suite #102, Madison, WI 53705, USA.
| |
Collapse
|
42
|
Fautsch MP, Johnson DH. Aqueous humor outflow: what do we know? Where will it lead us? Invest Ophthalmol Vis Sci 2006; 47:4181-7. [PMID: 17003404 PMCID: PMC2092444 DOI: 10.1167/iovs.06-0830] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Michael P Fautsch
- Department of Ophthalmology, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA.
| | | |
Collapse
|