Detection of Surfactant Proteins A and D in Human Tear Fluid and the Human Lacrimal System

Bräuer, Lars; Kindler, Christian; Jäger, Kristin; Sel, Saadettin; Nölle, Bernhard; Pleyer, Uwe; Ochs, Matthias; Paulsen, Friedrich

doi:10.1167/iovs.07-0201

Cited by 90 publications

(88 citation statements)

References 48 publications

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“…This finding was similar to that reported previously in human ocular structures. 13 This observation confirmed the specificity of the antibody used for SP-A detection. Glutamine synthetase has been shown to be a relatively specific marker of Müller cells in both the developing and mature retina.…”

Section: Sp-a and Its Expression In Retinasupporting

confidence: 64%

“…[7][8][9] Interestingly, these molecules have been found in organs other than those in the pulmonary system. [10][11][12] SP-A has been identified in vaginal and amniotic fluid, synovial fluid, the gastrointestinal tract, and the ocular surface, 13 thus broadening the possible function of these immunity-regulating proteins. SP-A on the corneal surface has been found to be an important mediator of bacterial clearance in the lacrimal/ocular system.…”

mentioning

confidence: 99%

“…[14][15][16] Investigation to this point has focused on the presence and role of SP-A and SP-D in the corneal and lacrimal system, including tear fluid, but little is known about the presence of SP-A or its potential role in the retina. 13,17,18 Deficiency of surfactant protein is a major contributor to lung disease of prematurity, as the premature lung has not yet acquired transcriptional potential sufficient to express surfactant and surfactant proteins. 19 After birth, various stressors, including hyperoxia, sepsis, and cytokines, can increase surfactant production.…”

mentioning

confidence: 99%

“…[23][24][25] Immunity-related signaling pathways that impact retinal and systemic angiogenesis in premature infants have not been well described. 13 Two important observations thus emerge: first, SP-A interacts with a host of cytokinemediating receptors throughout the body and has been found in ocular structures; and second, SP-A dysregulation plays an important role in preterm lung disease. Therefore SP-A upregulated in the retina in response to inflammatory signals may lead to aberrant blood vessel growth.…”

mentioning

confidence: 99%

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Pulmonary Surfactant Protein A Is Expressed in Mouse Retina by Muller Cells and Impacts Neovascularization in Oxygen-Induced Retinopathy

Bhatti

Ball

Hobbs

et al. 2014

Investigative Ophthalmology & Visual Science

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Section: Sp-a and Its Expression In Retinasupporting

confidence: 64%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Pulmonary Surfactant Protein A Is Expressed in Mouse Retina by Muller Cells and Impacts Neovascularization in Oxygen-Induced Retinopathy

Bhatti

Ball

Hobbs

et al. 2014

Investigative Ophthalmology & Visual Science

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show abstract

“…2,3 Comparable to their functions in the lung, surfactant proteins (SP)-B and SP-C have been suggested to operate in association with lipids of the tear film to break the surface tension of the tear film, which will be particularly important to prolong tear film break-up time. 3 The other two, SP-A and SP-D, do not show significant surface activity in the lung, but are innate immune defense lectins of the collectin family.…”

mentioning

confidence: 99%

Palate Lung Nasal Clone (PLUNC), a Novel Protein of the Tear Film: Three-Dimensional Structure, Immune Activation, and Involvement in Dry Eye Disease (DED)

Schicht

Rausch

Beron

et al. 2015

Invest. Ophthalmol. Vis. Sci.

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Citation: Schicht M, Rausch F, Beron M, et al. Palate lung nasal clone (PLUNC), a novel protein of the tear film: three-dimensional structure, immune activation, and involvement in dry eye disease (DED). Invest Ophthalmol Vis Sci. 2015;56:7312-7323. DOI:10.1167/iovs.15-17560 PURPOSE. Palate Lung Nasal Clone (PLUNC) is a hydrophobic protein belonging to the family of surfactant proteins that is involved in fluid balance regulation of the lung. Moreover, it is known to directly act against gram-negative bacteria. The purpose of this study was to investigate the possible expression and antimicrobial role of PLUNC at the healthy ocular surface and in tears of patients suffering from dry eye disease (DED).METHODS. Bioinformatics and biochemical and immunologic methods were combined to elucidate the structure and function of PLUNC at the ocular surface. Tissue-specific localization was performed by using immunohistochemistry. The PLUNC levels in tear samples from non-Sjögren's DED patients with moderate dry eye suffering either from hyperevaporation or tear deficiency were analyzed by ELISA and compared with tears from healthy volunteers.RESULTS. Palate Lung Nasal Clone is expressed under healthy conditions at the ocular surface and secreted into the tear film. Protein modeling studies and molecular dynamics simulations performed indicated surface activity of PLUNC. In vitro experiments revealed that proinflammatory cytokines and bacterial supernatants have only a slight effect on the expression of PLUNC in HCE and HCjE cell lines. In tears from DED patients, the PLUNC concentration is significantly increased (7-fold in evaporative dry eye tears and 17-fold in tears from patients with tear deficiency) compared with healthy subjects. CONCLUSIONS.The results show that PLUNC is a protein of the tear film and suggest that it plays a role in fluid balance and surface tension regulation at the ocular surface.

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Extrapulmonary Surfactant Therapy: Review of Available Data and Research/Development Issues

Foligno

Loi

Pezza

et al. 2020

The Journal of Clinical Pharma

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Since the discovery of surfactant, a large amount of knowledge has been accumulated about its biology and pharmacology. Surfactant is the cornerstone of neonatal respiratory critical care, but its proteins and phospholipids are produced in various tissues and organs, with possible roles only partially similar to that played in the alveoli. As surfactant research is focused mainly on its respiratory applications, knowledge about the possible role of surfactant in extrapulmonary disorders has never been summarized. Here we aim to comprehensively review the data about surfactant biology and pharmacology in organs other than the lung, especially focusing in the more promising surfactant extrapulmonary roles. We also review any preclinical or clinical data available about the therapeutic use of surfactant in these contexts. We offer a summary of knowledge and research/development milestones, as possible useful guidance for researchers of multidisciplinary background.

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Detection of Surfactant Proteins A and D in Human Tear Fluid and the Human Lacrimal System

Abstract: These results show that SP-A, in addition to SP-D, is a peptide of the tear film. Based on the known direct and indirect antimicrobial effects of collectins, the surfactant-associated proteins A and D seem to be involved in several ocular surface diseases.

Cited by 90 publications

References 48 publications

Pulmonary Surfactant Protein A Is Expressed in Mouse Retina by Muller Cells and Impacts Neovascularization in Oxygen-Induced Retinopathy

Pulmonary Surfactant Protein A Is Expressed in Mouse Retina by Muller Cells and Impacts Neovascularization in Oxygen-Induced Retinopathy

Palate Lung Nasal Clone (PLUNC), a Novel Protein of the Tear Film: Three-Dimensional Structure, Immune Activation, and Involvement in Dry Eye Disease (DED)

Extrapulmonary Surfactant Therapy: Review of Available Data and Research/Development Issues

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