Immunohistochemical Expression Of Fibronectin Research Articles

Cartilage differentiation in ependymoma: histogenetic considerations on a new case

The presence of cartilage in gliomas is a very unusual finding and has been mainly reported in ependymomas and in astrocytomas. A derivation of cartilage from neuroepithelial cells through a neuroepithelial-mesenchymal transition or directly from blood vessel-associated multipotent stromal elements has been proposed. We herein describe a further case of ependymoma with the presence of cartilage in a child affected by a tumor in the posterior fossa. In this case, only the last recurrence, characterized by focal areas of anaplasia, contained a nodule of cartilage. The immunohistochemical expression of fibronectin, tenascin-C, and CD44 was investigated, and the possible role of these molecules in the process of cartilage formation is discussed. Moreover, the literature on the subject is reviewed.

Osteopontin and Fibronectin Levels Are Decreased in Vitreous of Autoimmune Uveitis and Retinal Expression of Both Proteins Indicates ECM Re-Modeling

Autoimmune uveitis is an intraocular inflammation that arises through autoreactive T-cells attacking the inner eye, eventually leading to blindness. However, the contributing molecular pathomechanisms within the affected tissues remain as yet elusive. The extracellular matrix (ECM) is a highly dynamic structure that varies tremendously and influences the encompassing tissue. In order to assess ECM re-modeling in autoimmune uveitis, we investigated the expression of ECM molecules fibronectin and osteopontin in vitreous and retina samples. This was carried out in the only spontaneous animal model for human autoimmue uveitis, namely equine recurrent uveitis (ERU) that resembles the human disease in clinical as well as in immunopathological aspects. ERU is a naturally occurring autoimmune disease in horses that develops frequently and has already proved its value to study disease-related pathomechanisms. Western blot analysis of fibronectin and osteopontin in healthy and uveitic vitreous revealed significant reduction of both proteins in uveitis. Immunohistochemical expression of fibronectin in healthy retinas was restricted to the inner limiting membrane abutting vimentin positive Müller cell endfeet, while in uveitic sections, a disintegration of the ILM was observed changing the fibronectin expression to a dispersed pattern extending toward the vitreous. Retinal expression of osteopontin in control tissue was found in a characteristic Müller cell pattern illustrated by co-localization with vimentin. In uveitic retinas, the immunoreactivity of osteopontin in gliotic Müller cells was almost absent. The ability of Müller cells to express fibronectin and osteopontin was additionally shown by immunocytochemistry of primary cultured equine Müller cells and the equine Müller cell line eqMC-7. In conclusion, severe ECM re-modeling in autoimmune uveitis reported here, might affect the adhesive function of fibronectin and thus the anchoring of Müller cell endfeet to the ILM. Furthermore, the absence of osteopontin in gliotic Müller cells might represent reduced neuroprotection, an osteopontin attribute that is intensively discussed.

Immunohistochemical Expression of Fibronectin and Tenascin in Human Tooth Pulp Capped with Mineral Trioxide Aggregate and a Novel Endodontic Cement

Introduction The purpose of the present study was the immunohistochemical study of fibronectin (FN) and tenascin (TN) in human tooth pulp capped with mineral trioxide aggregate (MTA) and novel endodontic cement (NEC) (calcium enriched mixture cement) after 2 and 8 weeks. Methods Thirty-two premolar teeth that were scheduled for extraction for orthodontic reasons were exposed and capped with either MTA or NEC. The teeth were randomly divided into 4 groups: group 1 (NEC for 2 weeks), group 2 (NEC for 8 weeks), group 3 (MTA for 2 weeks), and group 4 (MTA for 8 weeks). After capping the exposed pulps with either NEC (groups 1 and 2) or MTA (groups 3 and 4), half of the specimens underwent extraction and were prepared for histologic and immunohistochemical evaluation for FN and TN after 2 weeks, and the remaining half were assessed after 8 weeks. FN and TN expression was scored by a blinded pathologist on a scale of I–IV, and the results were analyzed by the Wilcoxon and Mann-Whitney U statistical tests. Results FN and TN staining was observed in all 4 experimental groups, and there was no significant difference between expression of FN and TN in any groups. FN and TN staining was observed in the dentinal bridge matrix after 2 weeks under MTA. Expression of both markers reduced significantly after 8 weeks under MTA, and staining was observed only in unmineralized parts of dentinal bridge. FN and TN expression was observed in the matrix of the dentinal bridge after 2 weeks under NEC, and staining of both markers was reduced after 8 weeks compared with 2 weeks. The staining pattern of TN in NEC groups was higher than in MTA groups in both time intervals. However, the difference was not significant. Conclusions The present study demonstrated that both MTA and NEC are suitable biomaterials for direct pulp capping and are able to stimulate dentinal bridge formation. Moreover, the role of FN and TN as 2 major components of the matrix of a reparative dentinal bridge was observed.

Immunohistochemical expression of fibronectin and C5b-9 in the myocardium in cases of fatal ethanol intoxication

Data from the literature indicate that the pulmonary pressure rises in cases of ethanol intake. We have recently proposed a method for the detection of prevalent right ventricular damage in cases of fatal pulmonary thromboembolism and pulmonary fat embolism. In the present study, we compared the expression of the antibodies against fibronectin and C5b-9 in 19 cases of lethal alcohol intoxications (study group: 5 females, 14 males, mean age 46 years, mean blood ethanol concentration 3.5‰, min. 2.11‰, max. 5.31‰) to a group of 26 cases of fatal pulmonary thromboembolism (PE; group 2: 16 females, 10 males, mean age 56 years). Moreover, a group of 15 cases of hanging (group 3: 5 females, 10 males, mean age 50 years) as well as a group of 18 cases of myocardial infarction (group 4: 5 females, 13 males, mean age 61 years) were investigated as examples of typical cardiac damage due to global hypoxia during agony and ischemic damage, respectively. The results of this study show that fresh cardiac damage can be detected at both ventricles in cases of fatal ethanol intoxication with the antibody against fibronectin. The damage is prevalently localised at the right ventricle (RV), as already observed in cases of acute pulmonary hypertension determining right heart failure. The degree of damage at the RV in cases of ethanol intoxications is lower than the one observed in cases of fatal PE.

Immunohistochemical expression of fibronectin and C5b-9 in the myocardium in cases of carbon monoxide poisoning

Even if there is clinical evidence that carbon monoxide poisoning determines cardiac damage, the literature on the cardiac pathomorphology in such cases is scarce. We investigated the immunohistochemical expression of two known markers of fresh cardiac damage, fibronectin and the terminal complement complex C5b-9, in both cardiac ventricles in 26 cases of CO intoxication (study group, 15 ♀, 11 ♂, mean age 47years, mean COHb level 65.9%, min. 51%, max. 85%) compared to a group of 23 cases of hanging (n = 23, 4♀, 19♂, mean age 42years) as well as to 25 cases of myocardial infarction (n = 25, 13♀, 12♂, mean age 64years). Fresh cardiac damage was detected with the antibody fibronectin in cases of CO poisoning and was prevalently localised at the right ventricle.

Immunohistochemical expression of fibronectin in the lungs of fire victims proves intravital reaction in fatal burns

Immunohistochemical studies about the presence of fibronectin in the lungs were performed in a group of 73 fire victims (63 cases of intravital and 10 cases of postmortem burn) as well as in an unselected control group of 55 individuals not exposed to fire before death. The cases of intravital burn showed a significantly stronger fibronectin expression than the control cases and the cases of postmortem burn. Fibronectin was mainly present in macrophages of the peribronchial lung parenchyma and, not associated with cells, in the matrix of peribronchial tissue. Our findings suggest that higher levels of fibronectin expression in the lung tissue of burn victims compared to fire-unrelated deaths may serve as an indicator of an early intravital inflammatory response to fire damage.

Immunohistochemical expression of fibronectin and tenascin after direct pulp capping with calcium hydroxide

The aim of this study was to investigate the expression of 2 extracellullar matrix glycoproteins, fibronectin (FNC) and tenascin (TNC), following direct pulp capping with calcium hydroxide (CH). Third molars scheduled for extraction were used. Standardized class I cavities with pulp exposures were prepared. After control of bleeding, CH powder was applied in the exposure sites, which were covered with CH cement (Dycal; Dentsply) and the cavities were filled with zinc oxide-eugenol cement. Three teeth were extracted at each post-treatment period (1, 7, 14, and 30 days). Demineralized and paraffin-embedded specimens were stained for histologic technique (hematoxylin-eosin) and for immunohistochemical analysis. Anti-TNC and anti-FNC monoclonal antibodies were used with the streptavidin-biotin complex method. Generally, similar patterns of immunohistochemical expression were observed for TNC and FNC in the pulp tissue as a whole. In the exposure site, TNC immunostaining increased over time, exhibiting a thicker immunostaining pattern within 30 days. The imunohistochemical technique showed expression of both glycoproteins during pulp healing process.