Aberrant localization of ezrin correlates with salivary acini disorganization in Sjogren's Syndrome.

OBJECTIVES To analyse whether the alterations in the structure and organization of microvilli in salivary acinar cells from SS patients are linked to changes in the expression and/or cellular localization of ezrin. METHODS Salivary gland (SG) acini from controls and SS patients were used to evaluate ezrin expression by western blot and localization of total and activated (phospho-Thr567) ezrin by IF and EM. RESULTS In acini from control labial SGs, ezrin was located predominantly at the apical pole and to a lesser extent at the basal region of these cells. Conversely, in acini extracts from SS patients, ezrin showed significantly elevated levels, which were accompanied with localization mostly at the basal region. Moreover, F-actin maintained its distribution in both the apical region and basolateral cortex; however, it was also observed in the acinar cytoplasm. Phospho-ezrin (active form) was located exclusively at the apical pole of acinar cells from control subjects and abundantly located at the basal cytoplasm in SS samples. These results were confirmed by immunogold studies. CONCLUSIONS The decrease of ezrin and phospho-ezrin at the apical pole and the cytoplasmic redistribution of F-actin suggest an altered interaction between the F-actin-cytoskeleton and plasma membrane in SS patient acini, which may explain the microvilli disorganization. These alterations could eventually contribute to SG hyposecretion in SS patients.

[1]  A. Bretscher,et al.  Ezrin is concentrated in the apical microvilli of a wide variety of epithelial cells whereas moesin is found primarily in endothelial cells. , 1993, Journal of cell science.

[2]  P. Mangeat,et al.  ERM proteins in cell adhesion and membrane dynamics. , 1999, Trends in cell biology.

[3]  J. Hollyfield,et al.  Microvilli defects in retinas of ezrin knockout mice. , 2006, Experimental eye research.

[4]  L. Leyton,et al.  Enhanced degradation of proteins of the basal lamina and stroma by matrix metalloproteinases from the salivary glands of Sjögren's syndrome patients: correlation with reduced structural integrity of acini and ducts. , 2003, Arthritis and rheumatism.

[5]  T. Daniels.  Labial salivary gland biopsy in Sjögren's syndrome. Assessment as a diagnostic criterion in 362 suspected cases. , 1984, Arthritis and rheumatism.

[6]  A. Vaheri,et al.  Ezrin immunoreactivity in relation to survival in serous ovarian carcinoma patients. , 2003, Gynecologic oncology.

[7]  T. Matsui,et al.  Immunofluorescence detection of ezrin/radixin/moesin (ERM) proteins with their carboxyl-terminal threonine phosphorylated in cultured cells and tissues. , 1999, Journal of cell science.

[8]  A. Bretscher.  Regulation of cortical structure by the ezrin-radixin-moesin protein family. , 1999, Current opinion in cell biology.

[9]  X. Yao,et al.  Polarized distribution of actin isoforms in gastric parietal cells. , 1995, Molecular biology of the cell.

[10]  Zhong-ying Shen,et al.  Altered Expression of Ezrin in Esophageal Squamous Cell Carcinoma , 2006, The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society.

[11]  T. Noda,et al.  Achlorhydria by ezrin knockdown , 2005, The Journal of cell biology.

[12]  C. Delporte.  Aquaporins in secretory glands and their role in Sjögren's syndrome. , 2009, Handbook of experimental pharmacology.

[13]  J. Anaya,et al.  Gene expression and chromosomal location for susceptibility to Sjögren's syndrome. , 2009, Journal of autoimmunity.

[14]  Yoko Takahashi,et al.  Ezrin-radixin-moesin (ERM)-binding phosphoprotein 50 organizes ERM proteins at the apical membrane of polarized epithelia. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[15]  Christian Roy,et al.  Phosphoinositide binding and phosphorylation act sequentially in the activation mechanism of ezrin , 2004, The Journal of cell biology.

[16]  James M. Anderson,et al.  The unique-5 and -6 motifs of ZO-1 regulate tight junction strand localization and scaffolding properties. , 2007, Molecular biology of the cell.

[17]  Ying Wang,et al.  Ezrin/Radixin/Moesin Proteins Are Phosphorylated by TNF-α and Modulate Permeability Increases in Human Pulmonary Microvascular Endothelial Cells1 , 2006, The Journal of Immunology.

[18]  T. Gordon,et al.  Antimuscarinic antibodies in Sjögren's syndrome: where are we, and where are we going? , 2005, Arthritis and rheumatism.

[19]  M. Törnwall,et al.  Protein kinase C expression in salivary gland acinar epithelial cells in SjÖgren's syndrome , 1997, The Lancet.

[20]  L. Leyton,et al.  Involvement of specific laminins and nidogens in the active remodeling of the basal lamina of labial salivary glands from patients with Sjögren's syndrome. , 2006, Arthritis and rheumatism.

[21]  J. Anaya,et al.  Sjögren's syndrome comes of age. , 1999, Seminars in arthritis and rheumatism.

[22]  L. Leyton,et al.  Increased acinar damage of salivary glands of patients with Sjögren's syndrome is paralleled by simultaneous imbalance of matrix metalloproteinase 3/tissue inhibitor of metalloproteinases 1 and matrix metalloproteinase 9/tissue inhibitor of metalloproteinases 1 ratios. , 2005, Arthritis and rheumatism.

[23]  S. Rogers,et al.  Antimuscarinic antibodies in primary Sjögren's syndrome reversibly inhibit the mechanism of fluid secretion by human submandibular salivary acinar cells. , 2006, Arthritis and rheumatism.

[24]  R. Jonsson,et al.  Classification criteria for Sjögren's syndrome: a revised version of the European criteria proposed by the American-European Consensus Group , 2002, Annals of the rheumatic diseases.

[25]  Y. Yoon,et al.  The cytoskeletal protein ezrin regulates EC proliferation and angiogenesis via TNF-alpha-induced transcriptional repression of cyclin A. , 2005, The Journal of clinical investigation.

[26]  E. Kapsogeorgou,et al.  The Role of Epithelial Cells in the Pathogenesis of Sjögren’s Syndrome , 2007, Clinical reviews in allergy & immunology.

[27]  P. Fox,et al.  Cytokine expression in human labial minor salivary gland epithelial cells in health and disease. , 1999, Archives of oral biology.

[28]  R. Fox,et al.  Current issues in the diagnosis and treatment of Sjögren's syndrome. , 1999, Current opinion in rheumatology.

[29]  S. Brody,et al.  Foxj1 is required for apical localization of ezrin in airway epithelial cells , 2003, Journal of Cell Science.

[30]  M. Arpin,et al.  ERM proteins in epithelial cell organization and functions. , 2007, Biochimica et biophysica acta.

[31]  A. Bretscher,et al.  Identification of EBP50: A PDZ-containing Phosphoprotein that Associates with Members of the Ezrin-Radixin-Moesin Family , 1997, The Journal of cell biology.

[32]  Michiie Sakamoto,et al.  Altered Expression of the ERM Proteins in Lung Adenocarcinoma , 2000, Laboratory Investigation.

[33]  P. Fox,et al.  Sjogrens syndrome--the non-apoptotic model of glandular hypofunction. , 2006, Rheumatology.

[34]  A. McClatchey,et al.  Ezrin is essential for epithelial organization and villus morphogenesis in the developing intestine. , 2004, Developmental cell.

[35]  A. Bretscher,et al.  Ezrin oligomers are major cytoskeletal components of placental microvilli: a proposal for their involvement in cortical morphogenesis , 1995, The Journal of cell biology.

[36]  J. G. Forte,et al.  Functionally distinct pools of actin in secretory cells. , 2001, American journal of physiology. Cell physiology.

[37]  E. Veerman,et al.  Reduced sulfation of muc5b is linked to xerostomia in patients with Sjögren syndrome , 2007, Annals of the rheumatic diseases.