MUC7 Expression in the Human Lacrimal Gland and Conjunctiva

Jumblatt, Marcia M.; McKenzie, Richard W.; Steele, Pamela S.; Emberts, Celia G; Jumblatt, James E.

doi:10.1097/00003226-200301000-00010

Cited by 100 publications

(54 citation statements)

References 20 publications

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“…Similarly, our use of 2 different MUC7-specific antibodies on maximally loaded gels, with 10-fold more total tear protein than necessary for detection in the control secretion (saliva), confirms the findings of Jumblatt et al (Jumblatt et al, 2003) that the small soluble mucin MUC7, which is produced by lacrimal gland epithelia, is not present in human tear film. Since MUC5B and MUC7 proteins have been detected in lacrimal gland tissue (Paulsen et al, 2004), our data suggest that these two mucins are retained in the lacrimal gland where they may be produced and locally degraded.…”

Section: Discussionsupporting

confidence: 87%

“…MUC5B and MUC7 message and protein have been found in human lacrimal gland tissue (Jumblatt et al, 2003;Paulsen et al, 2004); however, previous assays did not detect the mucins in tears (Gipson et al, 2001;Jumblatt et al, 2003). To more conclusively demonstrate their presence or absence in tears, two additional antibodies specific for each of these mucins were used to probe immunoblots of maximally loaded gels (100μg of total tear protein) from a sample of pooled tears (N = 17).…”

Section: Selection Of Specific Mucin Antibodies For Detection Of Mucimentioning

confidence: 99%

“…MUC2 mRNA has been detected at low levels (5,900-fold lower than MUC5AC) in human conjunctival tissue, and MUC2 protein was detected by immunoblot of conjunctival tissue (McKenzie et al, 2000). Lacrimal gland epithelia have been shown to produce the small soluble secreted mucin MUC7 (Jumblatt et al, 2003), as well as MUC1, 5AC, and 5B (Paulsen et al, 2004), but it is not clear whether MUC7 and 5B are present in the tear fluid. Previous studies have demonstrated the presence of MUC1, 2, 4, and 5AC protein in human preocular tear fluid (Ellingham et al, 1997;Garcher et al, 1998;Jumblatt et al, 1999;McKenzie et al, 2000;Pflugfelder et al, 2000;Zhao et al, 2001;Argueso et al, 2002;Jumblatt et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

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Assay of mucins in human tear fluid

Spurr-Michaud

Argüeso

Gipson

2007

Experimental Eye Research

141

114

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Mucin genes, both secreted (MUC2, MUC5AC, MUC5B, MUC7) and membrane associated (MUC1, MUC4, MUC16), have been reported to be expressed by ocular surface epithelia. The purpose of this study was to comprehensively assay the mucin content of human tear fluid using multiple antibodies for each mucin and to develop a sensitive, semi-quantitative method for the assay of mucins in tears. Tear washes were obtained by instillation of saline onto the ocular surface, followed by collection from the inferior fornix. Tear proteins were separated in 1% agarose gels, transferred to nitrocellulose membrane by vacuum blotting and probed with multiple antibodies recognizing MUC1, MUC2, MUC4, MUC5AC, MUC5B, MUC7 and MUC16. Binding was detected using chemiluminescence, and quantity was determined by densitometry. Serial dilutions of pooled tears from normal individuals were assayed to determine the linear range of detectability. MUC1, MUC4, MUC16, MUC5AC and low levels of MUC2 were consistently detected in human tear fluid, while MUC5B and MUC7 were not. Use of several antibodies recognizing different epitopes on the same mucin confirmed these findings. The antibodies to mucins bound to serial dilutions of tears in a linear fashion (r 2 >0.9), indicating the feasibility of semi-quantitation. MUC5AC in tear fluid had an increased electrophoretic mobility compared to MUC5AC isolated from conjunctival tissue. This study provides clear evidence that the mucin component of tears is a mixture of secreted and shed membrane-associated mucins, and for the first time demonstrates MUC16 in tear fluid. Immunoblots of tears using agarose gel electrophoresis and chemiluminescence detection provide a semiquantitative assay for mucin protein that will be useful for comparisons with tears from diseased eyes or after pharmacological intervention.

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Section: Discussionsupporting

confidence: 87%

Section: Selection Of Specific Mucin Antibodies For Detection Of Mucimentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Assay of mucins in human tear fluid

Spurr-Michaud

Argüeso

Gipson

2007

Experimental Eye Research

141

114

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“…In this case, MUC5AC is not only produced by the goblet cells of excretory ducts but also by some acinar cells of the lacrimal gland (51). PCR analysis indicated that MUC1, MUC4, and MUC5B are expressed in human lacrimal tissue, but no in situ hybridization analysis has been performed to confirm their localization (39). In humans, MUC16 is present in the whole lacrimal apparatus (36).…”

Section: Muc Mrna Expression In Lacrimal Gland Acinar Cellsmentioning

confidence: 96%

α1-Adrenoceptors relate Ca2+ modulation and protein secretions in rat lacrimal gland

et al. 2015

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Noradrenaline (NA) is a catecholamine with multiple roles including as a hormone and a neurotransmitter. Cellular secretory activities are enhanced by adrenergic stimuli as well as by cholinergic stimuli. The present study aimed to determine which adrenoceptors play a role in controlling intracellular calcium ion ([Ca 2+ ] i ) level in acinar cells of rat lacrimal glands. Expression of mRNA for adrenoceptor subtypes in the acinar cells was assessed using RT-PCR. ] i increase. The peroxidase activity was quantified as a measure of mucin secretion. Ca 2+ -dependent exocytotic secretion of peroxidase was detected in rat lacrimal glands. The RT-PCR results showed that MUC1, MUC4, MUC5AC, MUC5B, and MUC16 were expressed in acinar cells. These findings indicated that NA activates α1-adrenoceptors, which were found to be the main receptors in Ca 2+ -related cell homeostasis and protein (including mucin) secretion in lacrimal glands.The lacrimal gland is the main contributor to the aqueous component of the preocular tear film, which contains water, electrolytes, proteins, peroxidase, mucins, and lactoferrin. The lacrimal gland is composed of several cell types, including myoepithelial cells, ductal cells, goblet cells, and acinar cells, which are the major cell type constituting 80% of the gland. Acinar cells are highly polarized and joined by tight junctions at the luminal membrane, creating distinct basolateral and apical membranes (12). Goblet cells are a source of mucus in tears and secrete different types of mucins onto the ocular surface, especially in the conjunctiva. Although the number of goblet cells increases in the nasolacrimal duct, as the diameter of the nasolacrimal duct lumen is narrower than that of the lacrimal sac. Regulation of lacrimal gland fluid secretions is under neural control; activation of the sensory nerves in the cornea and conjunctiva initiates an afferent pathway leading to the central nervous system, which subsequently activates an efferent pathway that stimulates parasympathetic and sympathetic nerves, and ultimately, the lacrimal gland (32). The appropriate amount and composition of lacrimal gland fluid are crucial for a healthy, intact ocular surface (14). Sympathetic nerves release the catecholamine noradrenaline (NA). Catecholamines bind to adreno-

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“…Dry eye patients su®er from discomfort such as sensitivity to light, stinging, burning, blurriness, grittiness, or scratchy and itchy eye. [1][2][3] Such experiences could arise from the ocular surface due to changes in the quantity and quality of the overlaying tears. The multiple causes of dry eye make its diagnoses and treatment di±cult.…”

Section: Introductionmentioning

confidence: 99%

A computer-based image analysis for tear ferning featuring

Saâd

El‐Hiti

Masmali

2015

J. Innov. Opt. Health Sci.

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The present work focuses on the development of a novel computer-based approach for tear ferning (TF) featuring. The original TF images of the recently developed¯ve-point grading scale have been used to assign a grade for any TF image automatically. A vector characteristic (VC) representing each grade was built using the reference images. A weighted combination between features selected from textures analysis using gray level co-occurrence matrix (GLCM), power spectrum (PS) analysis and linear speci¯city of the image were used to build the VC of each grade. A total of 14 features from texture analysis were used. PS at di®erent frequency points and number of line segments in each image were also used. Five features from GLCM have shown signi¯cant di®erences between the recently developed grading scale images which are: angular second moment at 0 and 45 , contrast, and correlation at 0 and 45 ; these¯ve features were all included in the characteristic vector. Three speci¯c power frequencies were used in the VC because of the discrimination power. Number of line segments was also chosen because of dissimilarities between images. A VC for each grade of TF reference images was constructed and was found to be signi¯cantly di®erent from each other's. This is a basic and fundamental step toward an automatic grading for computer-based diagnosis for dry eye.

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MUC7 Expression in the Human Lacrimal Gland and Conjunctiva

Cited by 100 publications

References 20 publications

Assay of mucins in human tear fluid

Assay of mucins in human tear fluid

<b>α1-Adrenoceptors relate Ca</b><sup><b>2+</b></sup><b> modulation and protein secretions in rat lacrimal </b><b>gland </b>

A computer-based image analysis for tear ferning featuring

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