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Oral Diseases (2012) 18, 713-719 Objectives: Heat shock protein (HSP) 27 is a low-molecular-weight protein that functions as a molecular chaperone and plays a cytoprotective role through its antioxidant activity during cell stress. Areca quid chewing is associated with the high incidence of oral squamous cell carcinomas (OSCCs) in Taiwan. The aim of this study was to compare heat shock protein 27 (HSP27) expression in OSCCs and the normal oral tissues. Methods: Forty-eight OSCCs from areca quid chewers and ten normal oral tissue biopsy samples without areca quid chewing were analyzed by immunohistochemistry for HSP27. The normal human oral keratinocytes (HOKs) were challenged with arecoline, the major alkaloid of areca nut, by Western blot for HSP27. Furthermore, epigallocatechin-3 gallate (EGCG), glutathione precursor N-acetyl- l-cysteine (NAC), cyclooxygenase-2 inhibitor NS-398, HSP inhibitor quercetin, extracellular signal-regulated protein kinase (ERK) inhibitor PD98059, and p38 inhibitor SB203580 were added to find the possible regulatory mechanisms. Results: Heat shock protein 27 exhibited higher expression in OSCCs than normal specimens ( P < 0.05). Arecoline was found to elevate HSP27 expression in a dose- and time-dependent manner ( P < 0.05). The additions of pharmacological agents were found to inhibit arecoline-induced HSP27 expression ( P < 0.05). Conclusions: Heat shock protein 27 expression is significantly elevated in areca quid chewing-associated OSCCs. Arecoline-induced HSP27 expression was downregulated by EGCG, NS398, NAC, quercetin, PD98059, and SB203580. [ABSTRACT FROM AUTHOR]

Oral Diseases (2010) 16, 696-701 Objectives: Hypoxia inducible factor (HIF)-1α gene expression is mainly induced by tissue hypoxia. Overexpression of HIF-1α has been demonstrated in a variety of cancers. The aim of this study was to compare HIF-1α expression in normal human oral epithelium and areca quid chewing-associated oral squamous cell carcinoma (OSCC) and further to explore the potential mechanisms that may lead to induce HIF-1α expression. Methods: Twenty-five OSCC from areca quid chewing-associated OSCC and 10 normal oral tissue biopsy samples without areca quid chewing were analyzed by immunohistochemistry. The oral epithelial cell line GNM cells were challenged with arecoline, a major areca nut alkaloid, by using Western blot analysis. Furthermore, glutathione precursor N-acetyl-l-cysteine (NAC), AP-1 inhibitor curcumin, extracellular signal-regulated protein kinase inhibitor PD98059, and protein kinase C inhibitor staurosporine were added to find the possible regulatory mechanisms. Results: Hypoxia inducible factor-1α expression was significantly higher in OSCC specimens than normal specimen ( P < 0.05). Arecoline was found to elevate HIF-1α expression in a dose- and time-dependent manner ( P < 0.05). The addition of NAC, curcumin, PD98059, and staurosporine markedly inhibited the arecoline-induced HIF-1α expression ( P < 0.05). Conclusions: Hypoxia inducible factor-1α expression is significantly upregulated in areca quid chewing-associated OSCC and HIF-1α expression induced by arecoline is downregulated by NAC, curcumin, PD98059, and staurosporine. [ABSTRACT FROM AUTHOR]

Chang T-Y, Tsai C-H, Chang Y-C. The upregulation of heat shock protein 47 in human gingival fibroblasts stimulated with cyclosporine A. J Periodont Res 2010; 45: 317–322. © 2009 John Wiley & Sons A/S Background and Objective: Heat shock protein 47 (Hsp47), a collagen-specific molecular chaperone, is involved in the processing and/or secretion of procollagen. Heat shock protein 47 is consistently and dramatically upregulated in a variety of fibrotic diseases. The aim of this study was to compare Hsp47 expression in normal gingival tissues and cyclosporine A-induced gingival overgrowth specimens and further explore the potential mechanisms that may lead to induction of Hsp47 expression. Material and Methods: Fifteen cyclosporine A-induced gingival overgrowth specimens and five normal gingival tissues were examined by immunohistochemistry. Western blot was used to investigate the effects of cyclosporine A on the expression of Hsp47 in human gingival fibroblasts. In addition, Aggregatibacter actinomycetemcomitans, interleukin-1α (IL-1α) and mitogen-activated protein kinase kinase (MEK) inhibitor U0126 were added to seek the possible regulatory mechanisms of Hsp47 expression. Results: A significantly higher percentage of cells positively stained for Hsp47 was noted in the cyclosporine A-induced gingival overgrowth group than in the normal gingival group ( p < 0.05). Expression of Hsp47 was observed mainly in the cytoplasm of fibroblasts, endothelial cells, epithelial cells and inflammatory cells. Expression of Hsp47 was significantly higher in cyclosporine A-induced gingival overgrowth specimens with higher levels of inflammatory infiltrates ( p < 0.05). Cyclosporine A upregulated Hsp47 expression in human gingival fibroblasts in a dose-dependent manner ( p < 0.05). The addition of A. actinomycetemcomitans or interlukin-1α significantly increased Hsp47 expression compared with cyclosporine A alone ( p < 0.05). The MEK inhibitor U0126 was found to inhibit cyclosporine A-induced Hsp47 expression ( p < 0.05). Conclusion: Expression of Hsp47 is significantly upregulated in cyclosporine A-induced gingival overgrowth specimens, and Hsp47 expression induced by cyclosporine A in fibroblasts may be mediated by the MEK signal transduction pathway. The expression of Hsp47 could be significantly enhanced by A. actinomycetemcomitans and interlukin-1α. [ABSTRACT FROM AUTHOR]

Background and Objective: Cystatin C is a 13 kDa non-glycosylated, basic protein belonging to the cystatin family. It is consistently and dramatically upregulated in a variety of fibrotic diseases. However, little is known about the correlation between cystatin C and cyclosporine A-induced gingival overgrowth. The aim of this study was to compare cystatin C expression in normal, healthy gingival tissues and cyclosporine A-induced gingival overgrowth specimens and further explore the potential mechanism that may result in cystatin C expression. Material and Methods: Fifteen cyclosporine A-induced gingival overgrowth specimens and five normal gingival tissues were examined by immunohistochemistry. Three human gingival fibroblast (HGF) strains were established from crown-lengthening surgery. The reverse transcriptase-polymerase chain reaction was used to investigate the effects on HGFs exposed to cyclosporine A. In addition, predominant periodontal pathogens ( Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis) and proinflammatory cytokines (interleukin-1α and tumor necrosis factor-α) were added to seek the possible regulatory mechanisms of cystatin C expression. Results: The cystatin C staining in gingival tissue was stronger in the cyclosporine A-induced gingival overgrowth group than in the normal gingival group ( p < 0.05). Intensive staining for cystatin C expression was observed mainly in the cytoplasm of fibroblasts, epithelial cells and inflammatory cells. Moreover, cystatin C expression was significantly higher in cyclosporine A-induced gingival overgrowth specimens with higher levels of inflammatory infiltrates ( p < 0.05). A concentration of 200 ng/mL cyclosporine A was found to increase cystatin C expression in HGFs in a time-dependent manner ( p < 0.05). The addition of periodontal pathogens and proinflammatory cytokines significantly increased the expression of cystatin C compared with cyclosporine A alone ( p < 0.05). Conclusion: The increased ability of protein accumulation by cystatin C is one of several factors mediating cyclosporine A-induced gingival overgrowth. In addition, cyclosporine A may predispose to gingival overgrowth in inflammatory environments. [ABSTRACT FROM AUTHOR]

Aim To compare oncostatin M (OSM) expression in clinically healthy and inflamed specimened human pulp tissue. Methodology Thirty pulpal tissue specimens (15 clinically healthy and 15 inflamed) were obtained from extracted third molars with informed consent from patients. The levels of OSM were compared between clinically healthy pulp and inflamed pulp tissues using the semi-quantitative reverse-transcriptase polymerase chain reaction. In addition, immunohistochemistry was used to identify the in situ localization of OSM expression in pulp specimens. For testing of differences in the OSM between the clinically healthy and inflamed human dental pulps, the Wilcoxon–Mann–Whitney rank sum test was applied. Differences in OSM expression between tissue with low and high levels of inflammation were subsequently analysed by Fisher’s exact test. Results Inflamed pulps exhibited significantly higher OSM mRNA gene expression than clinically healthy pulps ( P < 0.05). Immunohistochemistry demonstrated that OSM expression was significantly higher in inflamed than clinically healthy pulps ( P < 0.05). OSM staining was detected in odontoblasts, fibroblasts, inflammatory infiltrates and endothelial cells. Conclusions Oncostatin M expression was elevated in inflamed pulp tissue. OSM is potentially involved in the disease process of pulpal inflammation. [ABSTRACT FROM AUTHOR]

Aim To investigate the in situ location of oncostatin M (OSM) in epithelialized apical periodontitis lesions. Methodology Thirty periapical lesions of pulpal origin were collected with informed consent from patients at the time of apical surgery. Tissue specimens were fixed with 10% buffered formalin overnight, dehydrated in an ascending series of graded alcohol, and embedded in paraffin. Five micron sections from formalin-fixed, paraffin-embedded specimens were examined by immunohistochemistry. In addition, another section from each specimen was stained with haematoxylin and eosin to assess the presence of inflammatory infiltrates. Differences in OSM expression between tissue with low and high levels of inflammation were subsequently analyzed by Fisher’s exact test. Results Based on histological examination of haematoxylin and eosin stained sections, all specimens revealed the morphology of epithelialized apical periodontitis lesions. The results from immunohistochemistry demonstrated that OSM stain was detected in the inflammatory infiltrates, epithelium, connective tissue, and endothelium. The OSM signal was mainly expressed in endothelial cells (100%) followed by inflammatory cells (93.33%), epithelial cells (53.33%), and fibroblasts (16.67%). In addition, OSM expression was significantly higher in epithelialized apical periodontitis with higher levels of inflammatory infiltrates ( P < 0.001). Conclusions Oncostatin M was found to be expressed in epithelialized apical periodontitis lesions and would form part of the cytokine network involved in the disease process of apical periodontitis. [ABSTRACT FROM AUTHOR]

Huang F-M, Tsai C-H, Chen Y-J, Liu C-M, Chou M-Y, Chang Y-C.Upregulation of tissue-type plasminogen activator in inflamed human dental pulps.International Endodontic Journal,38, 328–333, 2005.To compare tissue-type plasminogen activator (t-PA) expression in normal human pulp and inflamed human pulp tissue specimens.Thirty pulpal tissue specimens (13 normal and 17 inflamed pulps) were obtained from extracted third molars. The levels of t-PA between normal pulp and inflamed pulp tissues were compared using the quantitative reverse-transcriptase polymerase chain reaction analysis. In addition, immunohistochemistry was used to identify thein situlocalization of t-PA expression in pulp specimens. Wilcoxon–Mann–Whitney rank sum test was applied for the statistical analysis of the results.t-PA mRNA gene was found more in inflamed pulps when compared with normal pulp tissue (P < 0.05). The results from immunohistochemistry demonstrated that t-PA expression was significantly higher in the inflamed pulp (P = 0.025). t-PA stain was detected in the fibroblasts, inflammatory infiltrates and endothelial cells.t-PA expression was significantly higher in inflamed pulp tissue. t-PA may play an important role in the pathogenesis of pulpal inflammation. [ABSTRACT FROM AUTHOR]

Abstract Tsai C-H, Huang F-M, Yang L-C, Chou M-Y, Chang Y-C. Immunohistochemical localization of cyclooxygenase-2 in radicular cysts. International Endodontic Journal, 35 , 854–858, 2002. Aim The purpose of this study was to investigate the expression of cyclooxygenase-2 (COX-2) in radicular cysts. Methodology Thirty biopsy specimens of radicular cysts were examined using immunohistochemistry. A peroxidase-labelled streptavidin–biotin technique was used for identification of the COX-2. Fisher's exact test (two-tail) was used for statistical analysis of the results. Results The result demonstrated that COX-2 expression was significantly higher in radicular cysts with higher levels of inflammatory infiltrates. COX-2 stain was detected in the lining epithelium, subepithelial fibroblasts, macrophages and endothelial cells in all specimens. Conclusions COX-2 expression is significantly higher in radicular cysts. COX-2 may play an important role in the pathogenesis of radicular cysts. [ABSTRACT FROM AUTHOR]