Expression and localization of aquaporin-1 in temporomandibular joint disc with internal derangement

J Oral Pathol Med. 2012 May 3. doi: 10.1111/j.1600-0714.2012.01156.x. [Epub ahead of print] Expression and localization of aquaporin-1 in temporomandibular joint disc with internal derangement. Loreto C, Galanti C, Almeida LE, Leonardi R, Pannone G, Musumeci G, Carnazza ML, Caltabiano R. Source Department of Bio-Medical Sciences, University of Catania, Catania, Italy Department of Dentistry, Faculty of Dentistry, University of Catania, Policlinico Universitario, Catania, Italy Center for Health and Biological Sciences, Pontifical Catholic, University of Panarà, Curitibe, Brazil Department of Surgical Sciences, Institute of Pathology and Cytopathology, University of Foggia, Foggia, Italy Department of Anatomy, Diagnostic Pathology, Forensic Medicine, Hygiene and Public Health, University of Catania, Catania, Italy. Abstract Internal derangement is the most J Oral Pathol Med (2012) Background: frequent arthropathy affecting the temporomandibular joint, where its commonest form is anterior disc displacement with or without reduction. Despite the frequency of the disorder, the biochemical features of displaced discs are still We investigated the expression pattern and localization of unclear. Methods: aquaporin-1, an important channel protein involved in plasma membrane water permeability, in patients with anterior disc displacement (both with and without reduction), with a view to assessing the characteristics of local tissue responses to the microenvironmental changes induced by abnormal mechanical loading of the displaced disc. Protein expression was studied by immunohistochemistry in different areas of discs from 18 patients with anterior disc displacement with or without reduction and in four normal controls. A greater proportion of cells immunopositive for aquaporin-1 were Results: detected in diseased than in normal discs. Whereas protein expression was substantially similar in the different areas of normal discs, a significantly larger number of immunopositive cells were detected in the posterior band of displaced discs without reduction and in the anterior and intermediate bands of These findings suggest that aquaporin-1 is those with reduction. Conclusions: expressed and upregulated in temporomandibular joint with anterior disc displacement (both with and without reduction).