Lubricin Immunohistochemical Expression in Human Temporomandibular Joint Disc with Internal Derangement

Lubricin is a chondroprotective, mucinous glycoprotein which contribute to joint lubrication, especially to boundary lubrication and maintains joint integrity. The present investigation aimed to study the immunolocalization of lubricin in TMJ discs from patients affected by anterior disc displacement with reduction (ADDwR) ADDwoR. Eighteen TMJ displaced disc affected by ADDwoR were processed immunohistochemically, with a polyclonal anti‐lubricin antibody, used at 1:50 working dilution. The percentage of lubricin immunopositive cells (extent score = ES) and the extent of lubricin staining of the disc extracellular matrix (ECM), were evaluated. Each sample was scored for histopathological changes. Percentage of immunostained surface disc cells was the same (ES = 4) in both control and ADDwOR cells, being this data not statistically significant (P \u3c 0.05). In pathological specimens the percentages of lubricin‐stained cells was very high with an ES of 4 respect to control specimen, and this difference was statistically significant different (P \u3e 0.05). The extracellular matrix (ECM) of discs at the disc surfaces of both pathological and normal specimens was very heavily stained (++++). Both the ES and ECM staining were not statistically correlated to the TMJ degeneration score according to the Spearman’s rank correlation coefficient. According to our findings, a longstanding TMJ disc injury, affects lubricin expression in the TMJ disc tissue and not its surfaces, moreover, lubricin immunostaining is not correlated to TMJ disc histopathological changes

Aquaporin and Vascular Diseases

Aquaporins (AQP) are family of water channels found in several epithelial and endothelial cells, whose recent identification has provided insights into water transport in several tissues, including the central nervous system (CNS). Since brain edema continues to be the main cause of death from several CNS diseases, such as stroke, much of the interest in AQPs and their functional contribution to the water balance is due to their possible role in clearing edema water from the brain and in managing hydrocephalus and benign intracranial hypertension, suggesting that they could be targets for future treatments of various brain conditions, particularly vascular diseases. AQPs also seem to be involved in cell migration, and a mechanism of AQP-facilitated cell migration has been proposed where local osmotic gradients created at the tip of the lamellipodium drive water influx, facilitating lamellipodial extension and cell migration. AQP-facilitated cell migration was also detected in tumour cells, suggesting that it may have an important role in tumour angiogenesis and spread, and accounting for AQP expression in many tumour cell types and for correlations found between AQP expression and tumour stage in some tumours

Apoptosis in Displaced Temporomandibular Joint Disc with and without Reduction: An Immunohistochemical Study

Internal derangement (ID) of the temporomandibular joint (TMJ) is due to an abnormal relationship of the articular disc to the mandibular condyle, glenoid fossa and articular eminence. The two most common types of internal derangement are anterior disc displacement with (ADDwR) and without reduction (ADDwoR). Disc displacement is associated with degenerative tissue changes. The histological features of discs from patients with TMJ ID reflect a general remodelling caused by abnormal loading. A correlation has been demonstrated between TMJ ID and apoptosis. Few investigations have addressed the role of apoptosis or caspase activity in TMJ ID. The apoptosis activation process was studied in different areas of discs from 18 patients with ID (both ADDwR and ADDwoR) and four cadavers (controls), with emphasis on the expression of caspase 3, whose activation makes the death process irreversible. The results showed a greater proportion of caspase 3‐positive cells in ADDwR and ADDwoR than in control discs. Immunopositivity also varied between disc areas; in particular, in ADDwoR sections labelled cells were significantly more numerous (P \u3c 0.01) in the posterior disc attachment than in the anterior and intermediate bands. In addition, a significantly greater proportion of labelled cells was seen in the anterior (+) and intermediate (++) band of ADDwR compared with ADDwoR discs both bands (P \u3c 0.05). These data suggest the importance of programmed cell death in the progression of TMJ ID

Occurrence and Regional Distribution of TRAIL and DR5 on Temporomandibular Joint Discs: Comparison of Disc Derangement with and without Reduction

Background Tumor necrosis factor (TNF)–related apoptosis-inducing ligand (TRAIL) is an apoptosis-inducing member of the TNF gene family which triggers apoptotic signals by interaction with its receptors. It has been suggested to be a major contributing factor to tissue degeneration. Objective The present study investigated, through immunohistochemistry, the regional expression of TRAIL and in temporomandibular joint (TMJ) disc of anterior disc displacement with reduction (ADDwR) and without reduction (ADDwoR) patients, to help determine the relationship between TMJ disc displacement and apoptosis. Study design We studied 18 TMJ diseased discs affected by disc displacement without or with reduction and 4 normal TMJ discs. Specimens were processed for immunohistochemistry to evaluate TRAIL and its receptor DR5 expression. Results Disc tissues from internal derangements (both ADDwR and ADDwoR) exhibited a much higher percentage of TRAIL- and DR5-positive cells as well as stain intensity compared with normal tissue though with regional variation according to the portion of the disc. There was a significantly higher percentage of stained cells in the posterior disc attachment compared with the anterior or intermediate bands of both ADDwR and ADDwoR discs for TRAIL and DR5. Conclusions TRAIL and DR5 are overexpressed in displaced human TMJ disc, especially in the posterior disc attachment. These results suggest a possible pivotal role of the TRAIL/DR5 system in TMJ disc degeneration

TRAIL, DR5 and Caspase 3-dependent Apoptosis in Vessels of Diseased Human Temporomandibular Joint Disc. An Immunohistochemical Study

To evaluate the apoptosis involvement in the angiogenesis as a self-limiting process in patients with temporomandibular joint (TMJ) degenerated disc vessels, we assessed, by immunohistochemistry, the detection of TRAIL, its death receptor DR5 and caspase 3. TRAIL, its death receptor DR5 and caspase 3 expression were studied by immunohistochemistry in 15 TMJ discs displaced without reduction and in 4 unaffected discs. These apoptosis molecules were detected in the intima and media layers of newly formed vessels affected discs. In conclusion, vessels apoptosis activation in TMJ disc with ID could be regarded as a self-limiting process that try to leads to vessel regression; in this way an inhibition of angiogenic vessels may prove a key strategy in limiting pathological angiogenesis, by cutting off blood supply to tumors, or by reducing harmful inflammation

Expression and Localization of aquaporin‐1 in Temporomandibular Joint Disc with Internal Derangement

Background: Internal derangement is the most 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 unclear. Methods: We investigated the expression pattern and localization of 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. Results: A greater proportion of cells immunopositive for aquaporin‐1 were 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 those with reduction. Conclusions: These findings suggest that aquaporin‐1 is expressed and upregulated in temporomandibular joint with anterior disc displacement (both with and without reduction)

ADAM10 Localization in Temporomandibular Joint Disk with Internal Derangement: An Ex Vivo Immunohistochemical Study

The purpose of this study was to determine the presence of ADAM10 in temporomandibular joint disk with internal derangement. Twenty-five paraffin blocks of displaced temporomandibular joint (TMJ) disk specimens from earlier investigations were retrieved from the archives of the University of Catania. Of these 16 had been removed from females and 9 from males; 11 with anterior disk displacement with reduction (ADDwR) and 14 with anterior disk displacement without reduction (ADDwoR). The sections were dehydrated, embedded in paraffin and cut. Then they were incubated in 0.3% H2O2/methanol and half of sections from each sample were incubated in diluted rabbit polyclonal anti-ADAM10 antibody. Then biotinylated anti-mouse/anti-rabbit IgG was applied to the sections, followed by avidin–biotin–perioxidase complex. The results were analyzed and the results were that ADAM10 was overexpressed in the posterior band of sections from patients with ADDwR compared to the other bands of both ADDwR and ADDwoR sections. Overexpression correlated with severe histopathological degeneration. We believe these results have the potential to provide insights into the pathogenesis of TMJ disk degeneration and to help design new therapeutic approaches targeting the proteolytic events that lead to tissue degeneration. Early therapeutic block of ADAM10 activity could succeed in limiting aggrecan-rich matrix breakdown without affecting normal physiology

A web-based system for tissue microarray data management

BACKGROUND: Tissue Microarray is a novel technique for analysing large amounts of immunohistochemically stained specimens. However, those large amounts make it difficult to design, prepare and analyze a tissue microarray, so that software support is almost inevitable. METHODS: We designed a tissue microarray data management system starting from specifications obtained by pathologists, and arranged for a preliminary validation in thyroid pathology. RESULTS: A web-based system has been developed, basing on open-source software and principles, that was well accepted by pathologists and allowed to carry out a study on 52 thyroid pathology cases. CONCLUSION: Though limited in functionalities, the developed system is effective and can be downloaded at the address

Expression of Interleukin-1 and Temporomandibular Disorder: Contemporary Review of the Literature

Objective: Temporomandibular disorders (TMD) are a group of conditions affecting the temporomandibular joint (TMJ), leading to jaw dysfunction, joint and muscle pain, and a decrease in quality of life. A communication network of pro- and anti-inflammatory mediators called cytokines maintains the homeostasis of the TMJ. This review will focus on the Interleukin (IL) family of cytokines, which have been quantified in TMJ synovial fluids in a variety of studies. IL-1α and IL-1β have pro-inflammatory effects, while the endogenous receptor antagonist (IL-1RA) inhibits the pro-inflammatory effects of IL-1. Methods: A literature search (2006–2016) to identify eligible studies was completed using the PubMed database. Studies identified used saline irrigation to quantify cytokine profiles in synovial fluid of healthy and/or dysfunctional joints. Results: The initial search yielded 111 articles, 5 of which met the inclusion criteria after inter-reviewer discussion. Conclusions: Articles that compared IL-1 concentrations in TMD vs. control groups found significant differences