Lacritin-induced secretion of tear proteins from cultured monkey lacrimal acinar cells

Atsuko Fujii, Ayumi Morimoto-Tochigi, Ryan D. Walkup, Thomas (Tom) Shearer, Mitsuyoshi Azuma

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

PURPOSE. During inflammation of the ocular surface, increased proinflammatory cytokines depress tear protein secretion, suggesting that a decline in lacrimal cell function contributes to dry eye. Lacritin, a glycoprotein secreted from lacrimal acinar cells, may function as an autocrine factor to stimulate tear protein secretion. The purpose of the present experiment was to investigate lacritin-induced protein secretion in normal and cytokine-pretreated (inflammation model) monkey acinar cells. METHODS. Acinar cells from monkey lacrimal glands were cultured with or without tumor necrosis factor alpha (TNF-α) plus interferon gamma (IFN-γ). Protein secretion was induced by lacritin or carbachol (Cch, positive control). Proteins were detected and identified by immunoblotting and immunocytochemistry. Intracellular Ca2+ was measured with the fluorophore Calcium-4, and cell damage was determined by LDH leakage into the culture medium. RESULTS. In cultured monkey acinar cells, lacritin stimulated tear protein secretion in normal cells without elevating intracellular Ca2+. In contrast, Cch elevated intracellular Ca2+ and release of tear proteins. This contrast suggested an alternate, calcium-independent mechanism for lacritin-induced protein secretion. TNF-α plus IFN-γ caused LDH leakage from sensitive human corneal epithelial cells, but even higher doses of TNF-α plus IFN-γ did not cause LDH leakage from monkey acinar cells, suggesting a higher tolerance against these cytokines. In cytokine-treated acinar cells, lacritin stimulated protein secretion as much as that in normal cells. In contrast, Cch-induced elevation of Ca2+ and release of proteins were depressed by cytokines. CONCLUSIONS. Lacritin might be a useful biotechnology-based treatment agent against ocular surface diseases where endogenous lacritin is inadequate.

Original languageEnglish (US)
Pages (from-to)2533-2540
Number of pages8
JournalInvestigative Ophthalmology and Visual Science
Volume54
Issue number4
DOIs
StatePublished - 2013

Fingerprint

Acinar Cells
Tears
Haplorhini
Cytokines
Proteins
Tumor Necrosis Factor-alpha
Inflammation
Calcium
Lacrimal Apparatus
Eye Diseases
Carbachol
Biotechnology
Immunoblotting
Interferon-alpha
Interferon-gamma
Culture Media
tear proteins
Glycoproteins
Epithelial Cells
Immunohistochemistry

Keywords

  • Cytokine
  • Lacrimal acinar cells
  • Lacritin
  • Monkey
  • Tear protein secretion

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

Cite this

Lacritin-induced secretion of tear proteins from cultured monkey lacrimal acinar cells. / Fujii, Atsuko; Morimoto-Tochigi, Ayumi; Walkup, Ryan D.; Shearer, Thomas (Tom); Azuma, Mitsuyoshi.

In: Investigative Ophthalmology and Visual Science, Vol. 54, No. 4, 2013, p. 2533-2540.

Research output: Contribution to journalArticle

Fujii, Atsuko ; Morimoto-Tochigi, Ayumi ; Walkup, Ryan D. ; Shearer, Thomas (Tom) ; Azuma, Mitsuyoshi. / Lacritin-induced secretion of tear proteins from cultured monkey lacrimal acinar cells. In: Investigative Ophthalmology and Visual Science. 2013 ; Vol. 54, No. 4. pp. 2533-2540.
@article{f0b73441ffeb4499ae45f061382f3b1e,
title = "Lacritin-induced secretion of tear proteins from cultured monkey lacrimal acinar cells",
abstract = "PURPOSE. During inflammation of the ocular surface, increased proinflammatory cytokines depress tear protein secretion, suggesting that a decline in lacrimal cell function contributes to dry eye. Lacritin, a glycoprotein secreted from lacrimal acinar cells, may function as an autocrine factor to stimulate tear protein secretion. The purpose of the present experiment was to investigate lacritin-induced protein secretion in normal and cytokine-pretreated (inflammation model) monkey acinar cells. METHODS. Acinar cells from monkey lacrimal glands were cultured with or without tumor necrosis factor alpha (TNF-α) plus interferon gamma (IFN-γ). Protein secretion was induced by lacritin or carbachol (Cch, positive control). Proteins were detected and identified by immunoblotting and immunocytochemistry. Intracellular Ca2+ was measured with the fluorophore Calcium-4, and cell damage was determined by LDH leakage into the culture medium. RESULTS. In cultured monkey acinar cells, lacritin stimulated tear protein secretion in normal cells without elevating intracellular Ca2+. In contrast, Cch elevated intracellular Ca2+ and release of tear proteins. This contrast suggested an alternate, calcium-independent mechanism for lacritin-induced protein secretion. TNF-α plus IFN-γ caused LDH leakage from sensitive human corneal epithelial cells, but even higher doses of TNF-α plus IFN-γ did not cause LDH leakage from monkey acinar cells, suggesting a higher tolerance against these cytokines. In cytokine-treated acinar cells, lacritin stimulated protein secretion as much as that in normal cells. In contrast, Cch-induced elevation of Ca2+ and release of proteins were depressed by cytokines. CONCLUSIONS. Lacritin might be a useful biotechnology-based treatment agent against ocular surface diseases where endogenous lacritin is inadequate.",
keywords = "Cytokine, Lacrimal acinar cells, Lacritin, Monkey, Tear protein secretion",
author = "Atsuko Fujii and Ayumi Morimoto-Tochigi and Walkup, {Ryan D.} and Shearer, {Thomas (Tom)} and Mitsuyoshi Azuma",
year = "2013",
doi = "10.1167/iovs.12-10394",
language = "English (US)",
volume = "54",
pages = "2533--2540",
journal = "Investigative Ophthalmology and Visual Science",
issn = "0146-0404",
publisher = "Association for Research in Vision and Ophthalmology Inc.",
number = "4",

}

TY - JOUR

T1 - Lacritin-induced secretion of tear proteins from cultured monkey lacrimal acinar cells

AU - Fujii, Atsuko

AU - Morimoto-Tochigi, Ayumi

AU - Walkup, Ryan D.

AU - Shearer, Thomas (Tom)

AU - Azuma, Mitsuyoshi

PY - 2013

Y1 - 2013

N2 - PURPOSE. During inflammation of the ocular surface, increased proinflammatory cytokines depress tear protein secretion, suggesting that a decline in lacrimal cell function contributes to dry eye. Lacritin, a glycoprotein secreted from lacrimal acinar cells, may function as an autocrine factor to stimulate tear protein secretion. The purpose of the present experiment was to investigate lacritin-induced protein secretion in normal and cytokine-pretreated (inflammation model) monkey acinar cells. METHODS. Acinar cells from monkey lacrimal glands were cultured with or without tumor necrosis factor alpha (TNF-α) plus interferon gamma (IFN-γ). Protein secretion was induced by lacritin or carbachol (Cch, positive control). Proteins were detected and identified by immunoblotting and immunocytochemistry. Intracellular Ca2+ was measured with the fluorophore Calcium-4, and cell damage was determined by LDH leakage into the culture medium. RESULTS. In cultured monkey acinar cells, lacritin stimulated tear protein secretion in normal cells without elevating intracellular Ca2+. In contrast, Cch elevated intracellular Ca2+ and release of tear proteins. This contrast suggested an alternate, calcium-independent mechanism for lacritin-induced protein secretion. TNF-α plus IFN-γ caused LDH leakage from sensitive human corneal epithelial cells, but even higher doses of TNF-α plus IFN-γ did not cause LDH leakage from monkey acinar cells, suggesting a higher tolerance against these cytokines. In cytokine-treated acinar cells, lacritin stimulated protein secretion as much as that in normal cells. In contrast, Cch-induced elevation of Ca2+ and release of proteins were depressed by cytokines. CONCLUSIONS. Lacritin might be a useful biotechnology-based treatment agent against ocular surface diseases where endogenous lacritin is inadequate.

AB - PURPOSE. During inflammation of the ocular surface, increased proinflammatory cytokines depress tear protein secretion, suggesting that a decline in lacrimal cell function contributes to dry eye. Lacritin, a glycoprotein secreted from lacrimal acinar cells, may function as an autocrine factor to stimulate tear protein secretion. The purpose of the present experiment was to investigate lacritin-induced protein secretion in normal and cytokine-pretreated (inflammation model) monkey acinar cells. METHODS. Acinar cells from monkey lacrimal glands were cultured with or without tumor necrosis factor alpha (TNF-α) plus interferon gamma (IFN-γ). Protein secretion was induced by lacritin or carbachol (Cch, positive control). Proteins were detected and identified by immunoblotting and immunocytochemistry. Intracellular Ca2+ was measured with the fluorophore Calcium-4, and cell damage was determined by LDH leakage into the culture medium. RESULTS. In cultured monkey acinar cells, lacritin stimulated tear protein secretion in normal cells without elevating intracellular Ca2+. In contrast, Cch elevated intracellular Ca2+ and release of tear proteins. This contrast suggested an alternate, calcium-independent mechanism for lacritin-induced protein secretion. TNF-α plus IFN-γ caused LDH leakage from sensitive human corneal epithelial cells, but even higher doses of TNF-α plus IFN-γ did not cause LDH leakage from monkey acinar cells, suggesting a higher tolerance against these cytokines. In cytokine-treated acinar cells, lacritin stimulated protein secretion as much as that in normal cells. In contrast, Cch-induced elevation of Ca2+ and release of proteins were depressed by cytokines. CONCLUSIONS. Lacritin might be a useful biotechnology-based treatment agent against ocular surface diseases where endogenous lacritin is inadequate.

KW - Cytokine

KW - Lacrimal acinar cells

KW - Lacritin

KW - Monkey

KW - Tear protein secretion

UR - http://www.scopus.com/inward/record.url?scp=84875971968&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84875971968&partnerID=8YFLogxK

U2 - 10.1167/iovs.12-10394

DO - 10.1167/iovs.12-10394

M3 - Article

C2 - 23482462

AN - SCOPUS:84875971968

VL - 54

SP - 2533

EP - 2540

JO - Investigative Ophthalmology and Visual Science

JF - Investigative Ophthalmology and Visual Science

SN - 0146-0404

IS - 4

ER -