Expression of hyaluronan synthase 3 in deformed human temporomandibular joint discs: in vivo and in vitro studies

The present study aimed at investigating the expression of a hyaluronan synthase (HAS) 3 in tissue samples of deformed human temporomandibular joint (TMJ) discs and cells obtained from the discs. Fifteen adult human TMJ discs (twelve diseased discs and three normal discs) were used in this study. The twelve diseased discs were obtained from twelve patients with internal derangement (ID) of TMJ. These patients all had anteriorly displaced discs and deformed discs. The tissues were immunohistochemically stained using HAS3 antibodies. In addition, the subcultured TMJ disc cells under both normal and hypoxic conditions (O2: 2%) were incubated for 3, 6, 12, and 24 h after addition of interleukin-1β (IL-1β) (1 ng/mL). Subsequently, the expression of HAS3 was examined using real-time reverse transcription-polymerase chain reaction (RT-PCR). The control group showed from negative to weak positive reactions for HAS3 on immunohistochemical staining. The discs extracted from twelve cases with ID presented from moderate to strong positive reactions for HAS3. The quantity of HAS3 mRNA was compared with a control group, and showed a 204-fold increase at 3 h, a 26-fold increase at 6 h, a 2.5-fold increase at 12 h and a 32-fold increase at 24 h under hypoxia with the addition of IL-1β. The expression of HAS3 mRNA was significantly enhanced at 3 h and 24 h. The results obtained suggest that HAS3 is related to the pathological changes of human TMJ discs affected by ID

Expression of lumican related to CD34 and VEGF in the articular disc of the human temporomandibular joint

Lumican belongs to the small leucine-rich repeat proteoglycan (SLRP) gene family and has been reported to exist in the cornea, intervertebral disc and tendon. Lumican plays a significant role in the assembly and regulation of collagen fibres. The human temporomandibular joint (TMJ) disc is made up of fibrocartilage with an extracellular matrix (ECM) composed of collagen and proteoglycans. The existence and behaviour of lumican have not been studied in the human TMJ disc. Therefore, we used immunohistochemical methods to detect lumican, CD34 and vascular endothelial growth factor (VEGF) and histochemical staining with toluidine blue in 13 human TMJ specimens (10 surgically removed and 3 obtained from autopsy). In both normal and deformed discs we observed staining with toluidine blue. We found that the area of metachromasia inside the deformed disc was uneven and expression of lumican was strong in the areas negative for metachromasia. Staining of VEGF and CD34 inside the deformed disc was seen. We confirmed the expression of lumican in the human TMJ disc and showed that a large number of fibroblast-like cells existed in the area of strong lumican expression. These new findings about the behaviour of lumican suggest that it may play a key role in the generation of a new collagen network by fibroblast-like cells

Tonsillar metastasis of gastric cancer

Metastasis from a malignant tumor to the palatine tonsils is rare, with only 100 cases reported in the English-language literature. Tonsillar metastasis from a gastric cancer is very rare. We report here a case of palatine tonsillar metastasis after gastric cancer surgery. The patient was an 88-year-old woman who had gastric cancer with abdominal wall invasion. She had undergone a distal gastrectomy with abdominal wall resection and D2 lymph node dissection. Histologically, the tumor was primarily a moderately differentiated adenocarcinoma. It was stage IV (T4, N1, M0) using TNM clinical classification. The patient developed pharyngeal discomfort and abdominal pain and was hospitalized during the follow-up period, 1 year 9 months post-operatively. Multiple lung metastases, Virchow’s lymph node metastasis, and adrenal metastasis were observed. A mass of 2.5 cm was also observed in the right palatine tonsil. It was diagnosed as a moderately differentiated adenocarcinoma, a metastasis from gastric cancer. There was a concern of asphyxiation due to hemorrhage of the tumor; however, the tumor dislodged approximately 10 days after biopsy and tonsillar recurrence was not observed. The patient died 1 year 10 months post-operatively. In the literature there are cases with tonsillar metastases where surgical treatment, radiotherapy, and chemotherapy were performed and extension of survival was seen. Tonsillar metastasis is a form of systemic metastasis of a malignant tumor, and there is a high risk for asphyxiation from tumor dislodgement or hemorrhage. Thus, it is important to recognize tonsillar metastasis as an oncologic emergency

Defects in muscarinic receptor-coupled signal transduction in isolated parotid gland cells after in vivo irradiation: evidence for a non-DNA target of radiation

Radiation-induced dysfunction of normal tissue, an unwanted side effect of radiotherapeutic treatment of cancer, is usually considered to be caused by impaired loss of cell renewal due to sterilisation of stem cells. This implies that the onset of normal tissue damage is usually determined by tissue turnover rate. Salivary glands are a clear exception to this rule: they have slow turnover rates (>60 days), yet develop radiation-induced dysfunction within hours to days. We showed that this could not be explained by a hypersensitivity to radiation-induced apoptosis or necrosis of the differentiated cells. In fact, salivary cells are still capable of amylase secretion shortly after irradiation while at the same time water secretion seems specifically and severely impaired. Here, we demonstrate that salivary gland cells isolated after in vivo irradiation are impaired in their ability to mobilise calcium from intracellular stores (Ca2+i), the driving force for water secretion, after exposure to muscarinic acetylcholine receptor agonists. Using radioligand-receptor-binding assays it is shown that radiation caused no changes in receptor density, receptor affinity nor in receptor-G-protein coupling. However, muscarinic acetylcholine agonist-induced activation of protein kinase C alpha (PKCα), measured as translocation to the plasma membrane, was severely affected in irradiated cells. Also, the phorbol ester PMA could no longer induce PKCα translocation in irradiated cells. Our data hence indicate that irradiation specifically interferes with PKCα association with membranes, leading to impairment of intracellular signalling. To the best of our knowledge, these data for the first time suggest that, the cells' capacity to respond to a receptor agonist is impaired after irradiation

Effect of interleukin-1beta and dehydroepiandrosterone on the expression of lumican and fibromodulin in fibroblast-like synovial cells of the human temporomandibular joint

Several epidemiological studies have reported that temporomandibular disorders (TMDs) are more prevalent in women than in men. It has recently been proposed that sex hormones such as estrogen, testosterone and dehydroepiandrosterone (DHEA) are involved with the pathogenesis of TMDs. Although studies have investigated the relationship between estrogen and testosterone and the restoration of TMDs, the relationship between DHEA and TMDs is unknown. The synovial tissue of the temporomandibular joint (TMJ) is made up of connective tissue with an extracellular matrix (ECM) composed of collagen and proteoglycan. One proteoglycan family, comprised of small leucine-rich repeat proteoglycans (SLRPs), was found to be involved in collagen fibril formation and interaction. In recent years, the participation of SLRPs such as lumican and fibromodulin in the internal derangement of TMJ has been suggested. Although these SLRPs may contribute to the restoration of the synovium, their effect is still unclear. The purpose of this study was to investigate the effect of DHEA, a sex hormone, on the expression of lumican and fibromodulin in human temporomandibular specimens and in cultured human TMJ fibroblast-like synovial cells in the presence or absence of the pro-inflammatory cytokine interleukin-1beta (IL-1beta). In the in vivo study, both normal and osteoarthritic (OA) human temporomandibular synovial tissues were immunohistochemically examined. In the in vitro study, five fibroblast-like synoviocyte (FLS) cell lines were established from human TMJ synovial tissue of patients with osteoarthritis. The subcultured cells were then incubated for 3, 6, 12 or 24 h with/without IL-1beta (1 ng/mL) in the presence or absence of DHEA (10 μM). The gene expression of lumican and fibromodulin was examined using the real-time polymerase chain reaction (PCR) and their protein expression was examined using immunofluorescent staining. We demonstrated that the expression of lumican significantly differs from that of fibromodulin in synovial tissue in OA and furthermore, that IL-1beta induced a significant increase in lumican mRNA and immunofluorescent staining in FLS compared to cells without IL-1beta. DHEA plus IL-1beta induced a significant increase in fibromodulin, but not in lumican mRNA, compared to DHEA alone, IL-1beta alone and in the absence of DHEA and IL-1beta. In immunofluorescent staining, weaker fibromodulin staining of FLS cells was observed in cells cultured in the absence of both DHEA and IL-1beta compared to fibromodulin staining of cells cultured with DHEA alone, with DHEA plus IL-1beta, or with IL-1beta alone. These results indicate that DHEA may have a protective effect on synovial tissue in TMJ by enhancing fibromodulin formation after IL-1beta induced inflammation. DHEA enhancement of fibromodulin expression may also exert a protective effect against the hyperplasia of fibrous tissue that TGF-beta1 induces. In addition lumican and fibromodulin are differentially expressed under different cell stimulation conditions and lumican and fibromodulin may promote regeneration of the TMJ after degeneration and deformation induced by IL-1beta.</p