1
|
Di Zazzo A, Barabino S, Fasciani R, Aragona P, Giannaccare G, Villani E, Rolando M. One Soul and Several Faces of Evaporative Dry Eye Disease. J Clin Med 2024; 13:1220. [PMID: 38592038 PMCID: PMC10932174 DOI: 10.3390/jcm13051220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 02/02/2024] [Accepted: 02/04/2024] [Indexed: 04/10/2024] Open
Abstract
The ocular surface system interacts with, reacts with, and adapts to the daily continuous insults, trauma, and stimuli caused by direct exposure to the atmosphere and environment. Several tissue and para-inflammatory mechanisms interact to guarantee such an ultimate function, hence maintaining its healthy homeostatic equilibrium. Evaporation seriously affects the homeostasis of the system, thereby becoming a critical trigger in the pathogenesis of the vicious cycle of dry eye disease (DED). Tear film lipid composition, distribution, spreading, and efficiency are crucial factors in controlling water evaporation, and are involved in the onset of the hyperosmolar and inflammatory cascades of DED. The structure of tear film lipids, and subsequently the tear film, have a considerable impact on tears' properties and main functions, leading to a peculiar clinical picture and specific management.
Collapse
Affiliation(s)
- Antonio Di Zazzo
- Ophthalmology Complex Operative Unit, Foundation Campus Bio-Medico University Hospital, 00128 Rome, Italy
- Ophthalmology Unit, Campus Bio-Medico University, 00128 Rome, Italy
| | - Stefano Barabino
- Ocular Surface & Dry Eye Center, ASST Fatebenefratelli SACCO, Kilan Univeristy, 20123 Milan, Italy;
| | - Romina Fasciani
- Ophthalmology Unit, “Fondazione Policlinico Universitario A. Gemelli IRCCS”, 00128 Rome, Italy;
- Ophtalmology Unit, Catholic University of “Sacro Cuore”, 00128 Rome, Italy
| | - Pasquale Aragona
- Ophthalmology Clinic, Department of Biomedical Sciences, University Hospital of Messina, 98122 Messina, Italy;
| | - Giuseppe Giannaccare
- Eye Clinic, Department of Surgical Sciences, University of Cagliari, 09124 Cagliari, Italy;
| | - Edoardo Villani
- Eye Clinic, San Giuseppe Hospital, IRCCS Multimedica, University of Milan, 20123 Milan, Italy;
| | - Maurizio Rolando
- Ocular Surface and Dry Eye Center, ISPRE Ophthalmics, 16129 Genoa, Italy;
| |
Collapse
|
2
|
Lee D, Song S, Cho G, Dalle Ore LC, Malmstadt N, Fuwad A, Kim SM, Jeon TJ. Elucidating the Molecular Interactions between Lipids and Lysozyme: Evaporation Resistance and Bacterial Barriers for Dry Eye Disease. NANO LETTERS 2023; 23:9451-9460. [PMID: 37842945 DOI: 10.1021/acs.nanolett.3c02936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Dry eye disease (DED) is a chronic condition characterized by ocular dryness and inflammation. The tear film lipid layer (TFLL) is the outermost layer composed of lipids and proteins that protect the ocular surface. However, environmental contaminants can disrupt its structure, potentially leading to DED. Although the importance of tear proteins in the TFLL functionality has been clinically recognized, the molecular mechanisms underlying TFLL-protein interactions remain unclear. In this study, we investigated tear protein-lipid interactions and analyzed their role in the TFLL functionality. The results show that lysozyme (LYZ) increases the stability of the TFLL by reducing its surface tension and increasing its surface pressure, resulting in increased TFLL evaporation and bacterial invasion resistance, with improved wettability and lubrication performance. These findings highlight the critical role of LYZ in maintaining ocular health and provide potential avenues for investigating novel approaches to DED treatment and patient well-being.
Collapse
Affiliation(s)
- Deborah Lee
- Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, United States
| | - Seoyoon Song
- Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, United States
| | - Geonho Cho
- Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Lucia C Dalle Ore
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, United States
| | - Noah Malmstadt
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, United States
| | - Ahmed Fuwad
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Sun Min Kim
- Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
- Department of Mechanical Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| | - Tae-Joon Jeon
- Department of Biological Sciences and Bioengineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
- Department of Biological Engineering, Inha University, 100 Inha-ro, Michuhol-gu, Incheon 22212, Republic of Korea
| |
Collapse
|
3
|
Riedlová K, Saija MC, Olżyńska A, Vazdar K, Daull P, Garrigue JS, Cwiklik L. Latanoprost incorporates in the tear film lipid layer: An experimental and computational model study. Int J Pharm 2023; 645:123367. [PMID: 37666309 DOI: 10.1016/j.ijpharm.2023.123367] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 08/29/2023] [Accepted: 09/01/2023] [Indexed: 09/06/2023]
Abstract
Glaucoma is a leading cause of blindness worldwide, with elevated intraocular pressure being a major risk factor for its development and progression. First-line treatment for glaucoma relies on the administration of prostaglandin analogs, with latanoprost being the most widely used. However, before latanoprost reaches the cornea, it must pass through the tear film and tear film lipid layer (TFLL) on the ocular surface. Given the significant lipophilicity of latanoprost, we hypothesize that TFLL could, to a certain extent, act as a reservoir for latanoprost, releasing it on longer time scales, apart from the fraction being directly delivered to the cornea in a post-instillation mechanism. We investigated this possibility by studying latanoprost behavior in acellular in vitro TFLL models. Furthermore, we employed in silico molecular dynamics simulations to rationalize the experimental results and obtain molecular-level insight into the latanoprost-TFLL interactions. Our experiments demonstrated that latanoprost indeed accumulates in the TFLL models, and our simulations explain the basis of the accumulation mechanism. These results support the hypothesis that TFLL can serve as a reservoir for latanoprost, facilitating its prolonged release. This finding could have significant implications for optimizing glaucoma treatment, especially in the development of new drug delivery systems targeting the TFLL.
Collapse
Affiliation(s)
- Kamila Riedlová
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic; Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 8, 12800 Prague, Czech Republic
| | - Maria Chiara Saija
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic; Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 8, 12800 Prague, Czech Republic
| | - Agnieszka Olżyńska
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic.
| | - Katarina Vazdar
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic
| | - Philippe Daull
- SANTEN SAS, Novagali Innovation Center, 1 rue Pierre Fontaine, Bâtiment Genavenir IV, CEDEX F-91458 Evry, France
| | - Jean-Sebastien Garrigue
- SANTEN SAS, Novagali Innovation Center, 1 rue Pierre Fontaine, Bâtiment Genavenir IV, CEDEX F-91458 Evry, France
| | - Lukasz Cwiklik
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic.
| |
Collapse
|
4
|
Scheuer CA, Barniak VL, Phatak NR, Rah MJ, Reindel W. Effect of Contact Lens Solutions in Stabilizing the Activity of Tear Lysozyme. CLINICAL OPTOMETRY 2023; 15:119-127. [PMID: 37205004 PMCID: PMC10187650 DOI: 10.2147/opto.s404261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 04/17/2023] [Indexed: 05/21/2023]
Abstract
Purpose Interactions between tear proteins and the interfaces of contact lenses can be complex and can influence contact lens wear success. Tear proteins, including lysozyme, function to maintain the balance of ocular surface homeostasis, as evidenced by the effects of its conformation relative to stabilizing the tear film and its potential impact on corneal epithelial cells. Contact lens manufacturers include components in lens care and blister package solutions to help stabilize the tear film and preserve homeostasis. This in vitro study was performed to evaluate the ability of daily disposable contact lens package solutions to stabilize lysozyme and preserve its native conformation under denaturing conditions. Methods Lysozyme was added to contact lens solutions sampled from kalifilcon A, etafilcon A, senofilcon A, narafilcon A, nelfilcon A, verofilcon A, delefilcon A, somofilcon A, and stenfilcon A blister packages, then mixed with the protein denaturant sodium lauryl sulfate. Lysozyme activity was evaluated by adding test solutions to a suspension of Micrococcus luteus. Native lysozyme lyses the Micrococcus luteus cell wall, which decreases suspension turbidity. Stabilization of lysozyme activity was determined by comparing suspension turbidity before and after exposure to test solutions. Results Lysozyme stabilization was 90.7% for kalifilcon A solution, a statistically significant improvement (p < 0.05) compared to phosphate buffered saline (PBS, negative control). No significant improvement was observed with any other contact lens solution (all lysozyme stabilization < 5.00%). Conclusion The representative tear protein lysozyme was significantly more stable in the novel kalifilcon A contact lens solution containing multiple moisturizers and osmoprotectants than in PBS or other daily disposable contact lens solutions. The lysozyme activity assay provides mechanistic evidence that the kalifilcon A contact lens solution can stabilize proteins under conditions that typically denature proteins, which may contribute to maintaining ocular surface homeostasis.
Collapse
Affiliation(s)
| | | | - Nitasha R Phatak
- Vision Care, Bausch & Lomb Inc., Rochester, NY, USA
- Correspondence: Nitasha R Phatak, Vision Care, Bausch & Lomb Incorporated, Rochester, NY, USA, Tel +1 585 413-6397, Email
| | | | | |
Collapse
|
5
|
Meng Z, Chu X, Zhang C, Liu H, Yang R, Huang Y, Zhao S. Efficacy and Safety evaluation of a single thermal pulsation system treatment (Lipiflow®) on meibomian gland dysfunction: a randomized controlled clinical trial. Int Ophthalmol 2022; 43:1175-1184. [PMID: 36112256 DOI: 10.1007/s10792-022-02516-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 09/11/2022] [Indexed: 10/14/2022]
Abstract
PURPOSE Evaluate the efficacy and safety of LipiFlow® thermal pulsation treatment system compared with lid massage combined warm compress in Chinese patients with meibomian gland dysfunction (MGD). METHODS Patients (n = 100 eyes, 50 subjects) diagnosed with MGD were recruited for this prospective, randomized, 3-month clinical trial. In Lipiflow group, patients (n = 50 eyes) received a single LipiFlow® thermal pulsation system treatment. In warm compress group, patients (n = 50 eyes) underwent warm compress daily for two weeks after an initial manual lid massage. Patients' symptoms were evaluated using Standard Patient Evaluation for Eye Dryness (SPEED) questionnaire. Safety parameters included best-corrected visual acuity (BCVA), intraocular pressure (IOP) and objective parameters including meibomian glands yielding lipid secretion (MGYLS) number, meibomian glands secretion (MGS) score, lipid layer thickness (LLT), tear-film breakup time (TBUT), corneal fluorescein staining (CFS) were measured and presented from baseline and to 3 months post-treatment. RESULTS Baseline parameters in both groups were comparable (p > 0.05). SPEED score and TBUT improved in two groups from baseline to 3 months. MGYLS number, MGS score, LLT improved in LipiFlow group and these improvements were maintained with no significant regression at 3 months. CFS showed significant improvement in warm compress group at 1 month compared with LipiFlow group. Moreover, the correlation analysis indicated LLT was positively correlated with TBUT, MGS score, and MGYLS number. CONCLUSION A single 12-min LipiFlow treatment is an effective therapy for MGD patients and can achieve improvements in symptoms alleviation and meibomian gland lipid secretion function lasting for at least 3 months.
Collapse
|
6
|
Sanchez V, Galor A, Jensen K, Mondal K, Mandal N. Relationships between ocular surface sphingomyelinases, Meibum and Tear Sphingolipids, and clinical parameters of meibomian gland dysfunction. Ocul Surf 2022; 25:101-107. [PMID: 35714913 DOI: 10.1016/j.jtos.2022.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 06/08/2022] [Accepted: 06/10/2022] [Indexed: 10/18/2022]
Abstract
PURPOSE Sphingolipids (SPL) are a class of lipid molecules that play important functional and structural roles in our body and are a component of meibum. Sphingomyelinases (SMases) are key enzymes in sphingolipid metabolism that hydrolyze sphingomyelin (SM) and generate ceramide (Cer). The purpose of this study was to examine relationships between ocular surface SMases, SPL composition, and parameters of Meibomian gland dysfunction (MGD). METHODS Individuals were grouped by meibum quality (n = 25 with poor-quality, MGD, and n = 25 with good-quality, control). Meibum and tears were analyzed with LC-MS to quantify SPL classes: Cer, Hexosyl-Ceramide (Hex-Cer), SM, Sphingosine (Sph), and sphingosine 1-phosphate (S1P). SMase activity in tears were quantified using a commercially available 'SMase assay'. Statistical analysis included multiple linear regression analyses to assess the impact of SMase activity on lipid composition, as well as ocular surface symptoms and signs of MGD. RESULTS Demographic characteristics were similar between the two groups. nSMase and aSMase levels were lower in the poor vs good quality group. aSMase activity in tears negatively correlated with SM in meibum and tears and positively with Sph in meibum and S1P in tears. Lower SMase activity were associated with signs of MGD, most notably Meibomian gland dropout. CONCLUSION This study suggests that individuals with MGD have reduced enzymatic activity of SMases in tears. Specifically, individuals with poor vs good meibum quality were noted to have alterations in SMase activity and SPL composition of meibum and tears which may reflect deviations from normal lipid metabolism in individuals with MGD.
Collapse
Affiliation(s)
- Victor Sanchez
- Miami Veterans Administration Medical Center, 1201 NW 16th St, Miami, FL, 33125, USA; New York University Grossman School of Medicine, New York, NY, 10016, USA
| | - Anat Galor
- Miami Veterans Administration Medical Center, 1201 NW 16th St, Miami, FL, 33125, USA; Bascom Palmer Eye Institute, University of Miami, 900 NW 17th Street, Miami, FL, 33136, USA
| | - Katherine Jensen
- Miami Veterans Administration Medical Center, 1201 NW 16th St, Miami, FL, 33125, USA
| | - Koushik Mondal
- Department of Ophthalmology, University of Tennessee Health Sciences Center, Hamilton Eye Institute, 930 Madison Avenue, Memphis, TN, 38163, USA
| | - Nawajes Mandal
- Department of Ophthalmology, University of Tennessee Health Sciences Center, Hamilton Eye Institute, 930 Madison Avenue, Memphis, TN, 38163, USA; Departments of Anatomy and Neurobiology, Pharmaceutical Sciences, University of Tennessee Health Sciences Center, 930 Madison Avenue, Memphis, TN, 38163, USA; Memphis VA Medical Center, 1030 Jefferson Avenue, Memphis, TN, 38104, USA.
| |
Collapse
|
7
|
Wang Y, Wang C. Novel Eye Drop Delivery Systems: Advance on Formulation Design Strategies Targeting Anterior and Posterior Segments of the Eye. Pharmaceutics 2022; 14:pharmaceutics14061150. [PMID: 35745723 PMCID: PMC9229693 DOI: 10.3390/pharmaceutics14061150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/18/2022] [Accepted: 05/25/2022] [Indexed: 11/30/2022] Open
Abstract
Eye drops are the most common and convenient route of topical administration and the first choice of treatment for many ocular diseases. However, the ocular bioavailability of traditional eye drops (i.e., solutions, suspensions, and ointments) is very low because of ophthalmic physiology and barriers, which greatly limits their therapeutic effect. Over the past few decades, many novel eye drop delivery systems, such as prodrugs, cyclodextrins, in situ gels, and nanoparticles, have been developed to improve ophthalmic bioavailability. These novel eye drop delivery systems have good biocompatibility, adhesion, and propermeation properties and have shown superior performance and efficacy over traditional eye drops. Therefore, the purpose of this review was to systematically present the research progress on novel eye drop delivery systems and provide a reference for the development of dosage form, clinical application, and commercial transformation of eye drops.
Collapse
|
8
|
The Potential Role of SP-G as Surface Tension Regulator in Tear Film: From Molecular Simulations to Experimental Observations. Int J Mol Sci 2022; 23:ijms23105783. [PMID: 35628592 PMCID: PMC9148136 DOI: 10.3390/ijms23105783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/11/2022] [Accepted: 05/18/2022] [Indexed: 12/07/2022] Open
Abstract
The ocular surface is in constant interaction with the environment and with numerous pathogens. Therefore, complex mechanisms such as a stable tear film and local immune defense mechanisms are required to protect the eye. This study describes the detection, characterization, and putative role of surfactant protein G (SP-G/SFTA2) with respect to wound healing and surface activity. Bioinformatic, biochemical, and immunological methods were combined to elucidate the role of SP-G in tear film. The results show the presence of SP-G in ocular surface tissues and tear film (TF). Increased expression of SP-G was demonstrated in TF of patients with dry eye disease (DED). Addition of recombinant SP-G in combination with lipids led to an accelerated wound healing of human corneal cells as well as to a reduction of TF surface tension. Molecular modeling of TF suggest that SP-G may regulate tear film surface tension and improve its stability through specific interactions with lipids components of the tear film. In conclusion, SP-G is an ocular surface protein with putative wound healing properties that can also reduce the surface tension of the tear film.
Collapse
|
9
|
Biochemistry of human tear film: A review. Exp Eye Res 2022; 220:109101. [DOI: 10.1016/j.exer.2022.109101] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 04/18/2022] [Accepted: 04/26/2022] [Indexed: 12/13/2022]
|
10
|
Xu X, Li G, Zuo YY. Biophysical properties of tear film lipid layer I. Surface tension and surface rheology. Biophys J 2022; 121:439-450. [PMID: 34958775 PMCID: PMC8822608 DOI: 10.1016/j.bpj.2021.12.033] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 12/04/2021] [Accepted: 12/22/2021] [Indexed: 02/03/2023] Open
Abstract
Tear film lipid layer (TFLL) is the outmost layer of the tear film. It plays a crucial role in stabilizing the tear film by reducing surface tension and retarding evaporation of the aqueous layer. Dysfunction of the TFLL leads to dysfunctional tear syndrome, with dry eye disease (DED) being the most prevalent eye disease, affecting 10%-30% of the world population. To date, except for treatments alleviating dry eye symptoms, effective therapeutic interventions in treating DED are still lacking. Therefore, there is an urgent need to understand the biophysical properties of the TFLL with the long-term goal to develop translational solutions in effectively managing DED. Here, we studied the composition-function correlations of an artificial TFLL, under physiologically relevant conditions, using a novel experimental methodology called constrained drop surfactometry. This artificial TFLL was composed of 40% behenyl oleate and 40% cholesteryl oleate, representing the most abundant wax ester and cholesteryl ester in the natural TFLL, respectively, and 15% phosphatidylcholine and 5% palmitic-acid-9-hydroxy-stearic-acid (PAHSA), which represent the two predominant polar lipid classes in the natural TFLL. Our study suggests that the major biophysical function of phospholipids in the TFLL is to reduce the surface tension, whereas the primary function of PAHSA is to optimize the rheological properties of the TFLL. These findings have novel implications in better understanding the physiological and biophysical functions of the TFLL and may offer new translational insight to the treatment of DED.
Collapse
Affiliation(s)
- Xiaojie Xu
- Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu
| | - Guangle Li
- Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu
| | - Yi Y. Zuo
- Department of Mechanical Engineering, University of Hawaii at Manoa, Honolulu,Department of Pediatrics, John A. Burns School of Medicine, University of Hawaii, Honolulu,Corresponding author
| |
Collapse
|
11
|
Galor A, Sanchez V, Jensen A, Burton M, Maus K, Stephenson D, Chalfant C, Mandal N. Meibum sphingolipid composition is altered in individuals with meibomian gland dysfunction-a side by side comparison of Meibum and Tear Sphingolipids. Ocul Surf 2022; 23:87-95. [PMID: 34861426 PMCID: PMC8792295 DOI: 10.1016/j.jtos.2021.11.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 01/21/2023]
Abstract
PURPOSE Sphingolipids (SPL) play a role in cell signaling, inflammation, and apoptosis. The purpose of this study was to examine meibum and tear SPL composition in individuals with poor versus good meibum quality. METHODS Individuals were grouped by meibum quality (n = 25 with poor quality, case group and n = 25 with good quality, control group). Meibum and tears were analyzed with liquid chromatography-mass spectrometry (LC-MS) to quantify SPL classes. Semiquantitative and relative composition (mole percent) of SPL and major classes, Ceramide (Cer), Hexosyl-Ceramide (Hex-Cer), Sphingomyelin (SM), Sphingosine (Sph), and sphingosine 1-phosphate (S1P) were compared between groups. RESULTS Demographic characteristics were similar between the two groups. Overall, individuals with poor meibum quality had more SPL pmole in meibum and tears than controls. Relative composition analysis revealed that individuals with poor meibum quality had SPL composed of less Cer, Hex-Cer, and Sph and more SM compared to individuals with good quality meibum. This pattern was not reproduced in tears as individuals with poor meibum quality had SPL composed of a similar amount of Cer, but more Hex-Cer, Sph and SM compared to controls. In meibum, SPL pmole and relative composition most strongly correlated with MG metrics while in tears, SPL pmole and relative composition most strongly correlated with tear production. SPL in both compartments, specifically Cer pmole in meibum and S1P% in tears, correlated with DE symptoms. CONCLUSION SPL composition differs in meibum and tears in patients with poor vs good meibum quality. These findings may be translated into therapeutic targets for disease.
Collapse
Affiliation(s)
- Anat Galor
- Miami Veterans Administration Medical Center, 1201 NW 16th St, Miami, FL 33125,Bascom Palmer Eye Institute, University of Miami, 900 NW 17th Street, Miami, FL 33136
| | - Victor Sanchez
- New York University Grossman School of Medicine, New York, NY 10016
| | - Andrew Jensen
- Miami Veterans Administration Medical Center, 1201 NW 16th St, Miami, FL 33125
| | - Madeline Burton
- Department of Ophthalmology, University of Tennessee Health Sciences Center, Hamilton Eye Institute, 930 Madison Avenue, Memphis, TN 38163
| | - Kenneth Maus
- Departments of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620
| | | | - Charles Chalfant
- Departments of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620,The Moffitt Cancer Center, Tampa, FL 33620,Research Service, James A. Haley Veterans Hospital, Tampa, FL 33612
| | - Nawajes Mandal
- Department of Ophthalmology, University of Tennessee Health Sciences Center, Hamilton Eye Institute, 930 Madison Avenue, Memphis, TN 38163,Departments of Anatomy and Neurobiology, and Pharmaceutical Sciences, University of Tennessee Health Sciences Center, 930 Madison Avenue, Memphis, TN 38163,Memphis VA Medical Center, 1030 Jefferson Avenue, Memphis, TN 38104.,Corresponding Author: Nawajes Mandal, PhD, 930 Madison Avenue, Suite 718, Memphis, TN 38163;
| |
Collapse
|
12
|
Tabernero J, Garcia-Porta N, Artal P, Pardhan S. Intraocular Scattering, Blinking Rate, and Tear Film Osmolarity After Exposure to Environmental Stress. Transl Vis Sci Technol 2021; 10:12. [PMID: 34379094 PMCID: PMC8362624 DOI: 10.1167/tvst.10.9.12] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Dry environments, such as those in offices or aircraft cabins, can potentially generate ocular discomfort and alter the tear film. We compare light scatter, blinking rate, and tear osmolarity in young and older subjects after exposure to low humidity using a controlled environmental chamber. Methods Two groups of healthy subjects were recruited; younger (N = 13, 27 ± 6 years) and older (N = 23, 71 ± 7 years). Measurements were carried out before and after 90-minute exposure to low relative humidity (5%) and constant temperature (23 degrees). Ocular light scatter was measured using a double-pass instrument (OQAS, Visiometrics, Spain). Blinking rate was monitored using an infrared video camera. Tear osmolarity was measured using the TearLab system (Escondido, CA, USA). Results Ocular light scatter increased by a factor of 10% after exposure to low humidity in the older group (P = 0.03) but did not change significantly in the younger group. Blinking rate increased significantly (40% more blinks) in both groups but there was no difference between the groups. No significant differences in osmolarity were shown between two age groups or as result of environmental stress. Conclusions Exposure to dry environment increased light scatter in older subjects. Although more blinks were triggered in both younger and older groups to prevent corneal dehydration, there was no difference between the groups. Blink rate and osmolarity are not associated with the difference in light scatter. Translational Relevance Our work approaches a clinical care problem using basic research methods (measuring ocular scatter and blink ratio).
Collapse
Affiliation(s)
- Juan Tabernero
- Vision and Eye Research Institute, Anglia Ruskin University, Cambridge, UK.,Departamento de Electromagnetismo y Electrónica, Universidad de Murcia, Spain
| | - Nery Garcia-Porta
- Vision and Eye Research Institute, Anglia Ruskin University, Cambridge, UK.,Vision and Hearing Sciences Research Centre, Anglia Ruskin University, Cambridge, UK
| | - Pablo Artal
- Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain
| | - Shahina Pardhan
- Vision and Eye Research Institute, Anglia Ruskin University, Cambridge, UK
| |
Collapse
|
13
|
Ewurum A, Ankem A, Georgiev G, Borchman D. A spectroscopic study of the composition and conformation of cholesteryl and wax esters purified from meibum. Chem Phys Lipids 2021; 238:105088. [PMID: 33965419 DOI: 10.1016/j.chemphyslip.2021.105088] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/20/2021] [Accepted: 05/02/2021] [Indexed: 10/21/2022]
Abstract
Elucidating wax ester (WE) and cholesteryl ester (CE) compositional, structural and functional relationships is key to our understanding of how these lipids are involved in natural and pathological processes. Little is known about how CE and WE interact with one another. The focus of the present study is to bridge this gap of knowledge. CE and WE were collected from human meibum as a source of esters with complex hydrocarbon chains. MgO column chromatography was used to separate WE and CE. The esters were characterized using 1H-NMR and Fourier transform infrared spectroscopy. The complexity of the hydrocarbon chains of native WE and CE influenced how changes in the ratio of WE and CE ester influenced some lipid phase transitional parameters but not others. Changes in CE content of WE/CE mixtures undoubtedly modifies the hydrocarbon chain conformation and packing of the mixture. The nature of the change depends on the conformation of the WE and CE. Differences in the complexity of the hydrocarbon chains are likely not to be a major influence on alterations in the order or phase transition temperature when more ordered WE is added to less ordered CE.
Collapse
Affiliation(s)
- Anthony Ewurum
- Department of Chemistry, University of Louisville, Louisville, KY, USA
| | - Akhila Ankem
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY, USA
| | - Georgi Georgiev
- iBB - Institute for Bioengineering and Biosciences, Interdisciplinary Complex, IST, University of Lisbon, 1649-004, Lisbon, Portugal
| | - Douglas Borchman
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY, USA.
| |
Collapse
|
14
|
Eftimov P, Olżyńska A, Melcrová A, Georgiev GA, Daull P, Garrigue JS, Cwiklik L. Improving Stability of Tear Film Lipid Layer via Concerted Action of Two Drug Molecules: A Biophysical View. Int J Mol Sci 2020; 21:E9490. [PMID: 33327408 PMCID: PMC7764870 DOI: 10.3390/ijms21249490] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/05/2020] [Accepted: 12/08/2020] [Indexed: 12/13/2022] Open
Abstract
The tear film at the ocular surface is covered by a thin layer of lipids. This oily phase stabilizes the film by decreasing its surface tension and improving its viscoelastic properties. Clinically, destabilization and rupture of the tear film are related to dry eye disease and are accompanied by changes in the quality and quantity of tear film lipids. In dry eye, eye drops containing oil-in-water emulsions are used for the supplementation of lipids and surface-active components to the tear film. We explore in detail the biophysical aspects of interactions of specific surface-active compounds, cetalkonium chloride and poloxamer 188, which are present in oil-in-water emulsions, with tear lipids. The aim is to better understand the macroscopically observed eye drops-tear film interactions by rationalizing them at the molecular level. To this end, we employ a multi-scale approach combining experiments on human meibomian lipid extracts, measurements using synthetic lipid films, and in silico molecular dynamics simulations. By combining these methods, we demonstrate that the studied compounds specifically interact with the tear lipid film enhancing its structure, surfactant properties, and elasticity. The observed effects are cooperative and can be further modulated by material packing at the tear-air interface.
Collapse
Affiliation(s)
- Petar Eftimov
- Department of Cytology and Embryology, Faculty of Biology, University of Sofia, 1504 Sofia, Bulgaria
| | - Agnieszka Olżyńska
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic
| | - Adéla Melcrová
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic
| | - Georgi As Georgiev
- iBB-Institute for Bioengineering and Biosciences, Complexo Interdisciplinar, IST, Universidade de Lisboa, 1649-004 Lisbon, Portugal
| | - Philippe Daull
- SANTEN SAS, Novagali Innovation Center, 1, rue Pierre Fontaine, Bâtiment Genavenir IV, CEDEX, F-91458 Evry, France
| | - Jean-Sebastien Garrigue
- SANTEN SAS, Novagali Innovation Center, 1, rue Pierre Fontaine, Bâtiment Genavenir IV, CEDEX, F-91458 Evry, France
| | - Lukasz Cwiklik
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague, Czech Republic
| |
Collapse
|
15
|
Rezende JDP, Coelho YL, de Paula HMC, da Silva LHM, Pires ACDS. Temperature modulation of lutein-lysozyme hydrophobic-hydrophilic interaction balance. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113887] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
16
|
Daull P, Amrane M, Ismail D, Georgiev G, Cwiklik L, Baudouin C, Leonardi A, Garhofer G, Garrigue JS. Cationic Emulsion-Based Artificial Tears as a Mimic of Functional Healthy Tear Film for Restoration of Ocular Surface Homeostasis in Dry Eye Disease. J Ocul Pharmacol Ther 2020; 36:355-365. [PMID: 32493105 PMCID: PMC7404832 DOI: 10.1089/jop.2020.0011] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 04/19/2020] [Indexed: 12/12/2022] Open
Abstract
Dry eye disease (DED) is a complex multifactorial disease that affects an increasing number of patients worldwide. Close to 30% of the population has experienced dry eye (DE) symptoms and presented with some signs of the disease during their lifetime. The significant heterogeneity in the medical background of patients with DEs and in their sensitivity to symptoms renders a clear understanding of DED complicated. It has become evident over the past few years that DED results from an impairment of the ocular surface homeostasis. Hence, a holistic treatment approach that concomitantly addresses the different mechanisms that result in the destabilization of the tear film (TF) and the ocular surface would be appropriate. The goal of the present review is to compile the different types of scientific evidence (from in silico modeling to clinical trials) that help explain the mechanism of action of cationic emulsion (CE)-based eye drop technology for the treatment of both the signs and the symptoms of DED. These CE-based artificial tear (AT) eye drops designed to mimic, from a functional point of view, a healthy TF contribute to the restoration of a healthy ocular surface environment and TF that leads to a better management of DE patients. The CE-based AT eye drops help restore the ocular surface homeostasis in patients who have unstable TF or no tears.
Collapse
Affiliation(s)
| | - Mourad Amrane
- Novagali Innovation Center, Santen SAS, Evry, France
| | - Dahlia Ismail
- Novagali Innovation Center, Santen SAS, Evry, France
| | - Georgi Georgiev
- Biointerfaces and Biomaterials Laboratory, Department of Optics and Spectroscopy, School of Optometry, Faculty of Physics, St. Kliment Ohridski University of Sofia, Sofia, Bulgaria
| | - Lukasz Cwiklik
- J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Christophe Baudouin
- CHNO des Quinze-Vingts, IHU FOReSIGHT, INSERM-DGOS CIC 1423, Paris, France & Sorbonne Universités, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Andrea Leonardi
- Department of Neuroscience, Ophthalmology Unit, University of Padua, Padua, Italy
| | - Gerhard Garhofer
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | | |
Collapse
|
17
|
Mixed polar-nonpolar lipid films as minimalistic models of Tear Film Lipid Layer: A Langmuir trough and fluorescence microscopy study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183300. [PMID: 32243884 DOI: 10.1016/j.bbamem.2020.183300] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 03/11/2020] [Accepted: 03/29/2020] [Indexed: 12/11/2022]
Abstract
The Tear Film Lipid Layer (TFLL) covering the surface of the aqueous film at human cornea forms a first barrier between the eye and environment. Its alterations are related to dry eye disease. TFLL is formed by a complex mixture of lipids, with an excess of nonpolar components and a minor fraction of polar molecules. Its thickness is up to 160 nm, hence a multilayer-like structure of TFLL is assumed. However, details of TFLL organization are mostly unavailable in vivo due to the dynamic nature of the human tear film. To overcome this issue, we employ a minimalistic in vitro lipid model of TFLL. We study its biophysical characteristics by using a combination of the Langmuir trough with fluorescence microscopy. The model consists of two-component polar-nonpolar lipid films with a varying component ratio spread on the aqueous subphase at physiologically relevant temperature. We demonstrate that the model lipid mixture undergoes substantial structural reorganization as a function of lateral pressure and polar to nonpolar lipid ratio. In particular, the film is one-molecule-thick and homogenous under low lateral pressure. Upon compression, it transforms into a multilayer structure with inhomogeneities in the form of polar-nonpolar lipid assemblies. Based on this model, we hypothesize that TFLL in vivo has a duplex polar-nonpolar structure and it contains numerous mixed lipid aggregates formed because of film restructuring. These findings, despite the simplified character of the model, seem relevant for TFLL physiology as well as for understanding pathological conditions related to the lipids of the tear film.
Collapse
|
18
|
Sabaghian S, Yazdian F, Rasekh B, Shekarriz M, Mansouri N. Investigating the effect of starch/Fe 3O 4 nanoparticles on biodesulfurization using molecular dynamic simulation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:1667-1676. [PMID: 31755060 DOI: 10.1007/s11356-019-06453-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 09/06/2019] [Indexed: 06/10/2023]
Abstract
The application of dibenzothiophene (DBT) as a source of energy leads to air pollution. The key solution to overcome this drawback is desulfurization. Magnetic nanoparticles have shown an excellent performance in the desulfurization of dibenzothiophene. In this study, molecular dynamic (MD) simulation was considered for the first time to gain insight about the molecule interactions in the biodesulfurization (BDS) process of DBT using Rhodococcus erythropolis IGTS8, in the presence and absence of starch/magnetic nanoparticles. According to the MD simulation results, the density of the system in the presence of starch/Fe3O4 was ascending while in the absence of these nanoparticles, the density was descending. Starch/magnetic nanoparticles caused more rapid equilibrium state in the biodesulfurization process. The energy diagram showed that magnetic nanoparticles decrease the energy fluctuation and increase the difference of non-bounding energy and potential energy (8 times) compared to (BDS) without nanoparticle, which reflects higher bounded energy in the system using starch/magnetic nanoparticles. The height of RDF peak in the presence of starch/Fe3O4 was 4 times more than the RDF peak in the absence of nanoparticle. In addition, the nanoparticles decreased the fluctuations around optimal temperature in BDS up to 5% compared to other state.
Collapse
Affiliation(s)
- Soltan Sabaghian
- Department of Environmental Science, Faculty of Natural Resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Fatemeh Yazdian
- Department of Life Science Engineering, Faculty of New Science and Technologies, University of Tehran, Tehran, Iran.
| | - Behnam Rasekh
- Research Institute of Petroleum Industry (RIPT), P.O. Box 1485733111, Tehran, Iran.
| | - Marziyeh Shekarriz
- Chemical, Polymeric and Petrochemical Technology Development Division, Faculty of Downstream Technology Development, Research Institute of Petroleum Industry, Tehran, Iran
| | - Nabiallah Mansouri
- Department of Environmental Engineering, Faculty of Natural Resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran
| |
Collapse
|
19
|
Zhang R, Zhang N, Mohri M, Wu L, Eckert T, Krylov VB, Antosova A, Ponikova S, Bednarikova Z, Markart P, Günther A, Norden B, Billeter M, Schauer R, Scheidig AJ, Ratha BN, Bhunia A, Hesse K, Enani MA, Steinmeyer J, Petridis AK, Kozar T, Gazova Z, Nifantiev NE, Siebert HC. Nanomedical Relevance of the Intermolecular Interaction Dynamics-Examples from Lysozymes and Insulins. ACS OMEGA 2019; 4:4206-4220. [PMID: 30847433 PMCID: PMC6398350 DOI: 10.1021/acsomega.8b02471] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 11/28/2018] [Indexed: 06/01/2023]
Abstract
Insulin and lysozyme share the common features of being prone to aggregate and having biomedical importance. Encapsulating lysozyme and insulin in micellar nanoparticles probably would prevent aggregation and facilitate oral drug delivery. Despite the vivid structural knowledge of lysozyme and insulin, the environment-dependent oligomerization (dimer, trimer, and multimer) and associated structural dynamics remain elusive. The knowledge of the intra- and intermolecular interaction profiles has cardinal importance for the design of encapsulation protocols. We have employed various biophysical methods such as NMR spectroscopy, X-ray crystallography, Thioflavin T fluorescence, and atomic force microscopy in conjugation with molecular modeling to improve the understanding of interaction dynamics during homo-oligomerization of lysozyme (human and hen egg) and insulin (porcine, human, and glargine). The results obtained depict the atomistic intra- and intermolecular interaction details of the homo-oligomerization and confirm the propensity to form fibrils. Taken together, the data accumulated and knowledge gained will further facilitate nanoparticle design and production with insulin or lysozyme-related protein encapsulation.
Collapse
Affiliation(s)
- Ruiyan Zhang
- Institute
of Biopharmaceutical Research, Liaocheng
University, Liaocheng 252059, P. R. China
- RI-B-NT
Research Institute of Bioinformatics and Nanotechnology, Franziusallee 177, 24148 Kiel, Germany
- Institute
of Zoology, Department of Structural Biology, Christian-Albrechts-University, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Ning Zhang
- Institute
of Biopharmaceutical Research, Liaocheng
University, Liaocheng 252059, P. R. China
| | - Marzieh Mohri
- RI-B-NT
Research Institute of Bioinformatics and Nanotechnology, Franziusallee 177, 24148 Kiel, Germany
| | - Lisha Wu
- Department
of Chemical and Biological Engineering, Chalmers University of Technology, 41296 Gothenburg, Sweden
| | - Thomas Eckert
- Department
of Chemistry and Biology, University of
Applied Sciences Fresenius, Limburger Str. 2, 65510 Idstein, Germany
- Institut
für Veterinärphysiolgie und Biochemie, Fachbereich Veterinärmedizin, Justus-Liebig-Universität Gießen, Frankfurter Str. 100, 35392 Gießen, Germany
| | - Vadim B. Krylov
- Laboratory
of Glycoconjugate Chemistry, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prospect 47, 119991 Moscow, Russian Federation
| | - Andrea Antosova
- Department
of Biophysics Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Slavomira Ponikova
- Department
of Biophysics Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Zuzana Bednarikova
- Department
of Biophysics Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Philipp Markart
- Medical
Clinic II, Justus-Liebig-University, Klinikstraße 33, 35392 Giessen, Germany
- Pneumology,
Heart-Thorax-Center Fulda, Pacelliallee 4, 36043 Fulda, Germany
| | - Andreas Günther
- Medical
Clinic II, Justus-Liebig-University, Klinikstraße 33, 35392 Giessen, Germany
| | - Bengt Norden
- Department
of Chemical and Biological Engineering, Chalmers University of Technology, 41296 Gothenburg, Sweden
| | - Martin Billeter
- Department
of Chemistry and Molecular Biology, University
of Gothenburg, 40530 Gothenburg, Sweden
| | - Roland Schauer
- Institute
of Biochemistry, Christian-Albrechts-University, Olshausenstrasse 40, 24098 Kiel, Germany
| | - Axel J. Scheidig
- Institute
of Zoology, Department of Structural Biology, Christian-Albrechts-University, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Bhisma N. Ratha
- Biomolecular
NMR and Drug Design Laboratory, Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), 700054 Kolkata, India
| | - Anirban Bhunia
- Biomolecular
NMR and Drug Design Laboratory, Department of Biophysics, Bose Institute, P-1/12 CIT Scheme VII (M), 700054 Kolkata, India
| | - Karsten Hesse
- Tierarztpraxis
Dr. Karsten Hesse, Rathausstraße
16, 35460 Stauffenberg, Germany
| | - Mushira Abdelaziz Enani
- Infectious
Diseases Division, Department of Medicine, King Fahad Medical City, P.O. Box 59046, 11525 Riyadh, Kingdom of Saudi
Arabia
| | - Jürgen Steinmeyer
- Laboratory
for Experimental Orthopaedics, Department of Orthopaedics, Justus-Liebig-University, Paul-Meimberg-Str. 3, D-35392 Giessen, Germany
| | - Athanasios K. Petridis
- Neurochirurgische
Klinik, Universität Düsseldorf, Geb. 11.54, Moorenstraße 5, 40255 Düsseldorf, Germany
| | - Tibor Kozar
- Center
for Interdisciplinary Biosciences, TIP-UPJS, Jesenna 5, 04001 Kosice, Slovakia
| | - Zuzana Gazova
- Department
of Biophysics Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Kosice, Slovakia
| | - Nikolay E. Nifantiev
- Laboratory
of Glycoconjugate Chemistry, N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prospect 47, 119991 Moscow, Russian Federation
| | - Hans-Christian Siebert
- RI-B-NT
Research Institute of Bioinformatics and Nanotechnology, Franziusallee 177, 24148 Kiel, Germany
| |
Collapse
|
20
|
Patel R, Zhu M, Robertson DM. Shifting the IGF-axis: An age-related decline in human tear IGF-1 correlates with clinical signs of dry eye. Growth Horm IGF Res 2018; 40:69-73. [PMID: 29452886 PMCID: PMC5984117 DOI: 10.1016/j.ghir.2018.02.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 01/22/2018] [Accepted: 02/04/2018] [Indexed: 12/01/2022]
Abstract
OBJECTIVE The human corneal epithelium expresses both the insulin-like growth factor type 1 receptor (IGF-1R) and the IGF-1R/insulin receptor (INSR) hybrid. Despite the previous identification of IGF-1 in human tear fluid, little is known regarding the regulation of IGF-1 in tear fluid and its role in corneal epithelial homeostasis. In the present study, we investigated the impact of biological parameters on the concentration of human tear levels of IGF-1. DESIGN Tear levels of IGF-1 were measured in 41 healthy, human volunteers without any reported symptoms of dry eye. All volunteers underwent standard biomicroscopic examination of the cornea and tear film. In a subgroup of volunteers, corneal staining with sodium fluorescein, tear film break up time and tear production using a Schirmer's test strip were measured to assess clinical signs of dry eye. Tears were collected from the inferior tear meniscus using glass microcapillary tubes and IGF-1 levels were measured using a solid phase sandwich ELISA. RESULTS Tear levels of IGF-1 were highest in young adults and significantly decreased in older adults (P = 0.003). There were no differences in tear IGF-1 between males and females (P = 0.628). Tear IGF-1 levels were correlated with tear film break up time (R = 0.738) and tear production (R = 0.826). CONCLUSIONS These data indicate that there is a progressive decline in tear IGF-1 due to aging that is associated with clinical signs of dry eye. This effect is likely due to age-related changes in the lacrimal gland.
Collapse
Affiliation(s)
- Roshni Patel
- The Department of Ophthalmology, UT Southwestern, United States
| | - Meifang Zhu
- The Department of Ophthalmology, UT Southwestern, United States
| | | |
Collapse
|