A novel experimental model to investigate fungal involvement shows expression of Dectin-1 in periapical lesion pathogenesis.

BACKGROUND: Candida albicans is linked to persistent endodontic lesions. However, the recognition receptor that identifies it is not explored previously. OBJECTIVES: The aim of this study was to (1) establish a zymosan-induced model of apical periodontitis in mouse, (2) observe the expression of Dectin-1 and its possible relationship with toll-like receptor (TLR) 2 and (3) observe relationship between Osteopontin (OPN) and inflammatory cytokines. METHODS: A total of 138 Naval Medical Research Institute (NMRI) mice were randomly divided into; Experimental Group n = 69 and Zymosan Group n = 69. Periapical periodontitis was developed in right maxillary molar. The animals were sacrificed at 7, 21 and 42 days. Bone blocks containing the mesial root (n = 15 for qRT-PCR, n = 45 for enzyme-linked immune sorbent assay (ELISA)) were collected for mRNA expression and ELISA. While whole maxilla (n = 3 from each time interval) were used for histology and immunohistochemical analysis. One way analysis of variance (ANOVA) and Tuckey's posthoc was used for statistical analysis at p ≤ .05. RESULTS: TLR-2, Dectin-1 and TLR4-positive cells was detected at all time intervals in both groups. A strong positive correlation was observed between TLR-2 and Dectin-1 in both lesions (regular r = .680, p = .015, zymosan (r = .861, p < .001)). A significant correlation was found between OPN and tumour necrosis factor-alpha (TNF-α) in zymosan lesion (r = .827, p = .001). CONCLUSIONS: Immune cells of inflamed periapical tissue expressed Dectin-1 receptor in response to the microbial challenge from infected root canals and showed positive correlation with TLR-2 and OPN suggesting a possible receptor collaboration mediated by OPN. The expression of OPN and TNF-α showed positive correlation in response to fungal antigen, indicating a possible relationship.

Expression of Toll-like receptor 2, Dectin-1, and Osteopontin in murine model of pulpitis.

OBJECTIVES: This in vivo animal study aimed to develop a murine model of pulpitis induced by pulp exposure with or without application of zymosan in Naval Medical Research Institute (NMRI) mice and observe expressions of Toll-like receptor (TLR)-2, TLR-4, Dectin-1, Osteopontin (OPN), tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and IL-1ß. MATERIAL AND METHODS: A total of 168 NMRI mice were divided into two groups, i.e., group A (n = 84) (pulpitis induced by pulp exposure only) and group B (n = 84) (pulpitis induced by pulp exposure and zymosan application). Right maxillary molar pulps were exposed with » round bur, and animals were sacrificed at 0, 6, 9, 12, 24, 48, and 72 h. The exposed teeth were obtained for real-time polymerase chain reaction (qRT-PCR) analysis and histological and immunohistochemistry (IHC) analysis. RESULTS: Histological evaluation revealed a time-dependent steady increase in inflammation. Similar time-dependent increase in the expression of inflammatory cytokines was noted. Group A exhibited an increase in TLR-4, Dectin-1, and OPN at 6 h, while TLR-2 was expressed at 24 h. Group B expressed TLR-2, Dectin-1, and OPN at 9, 48, and 72 h, respectively (p ≤ 0.05). Expression of OPN and TNF-α exhibited a similar pattern in both groups. IHC also detected expression of TLR-2, Dectin-1, TLR4, and CD68 in some cells at 6 and 9 h. CONCLUSIONS: NMRI mice provided for a stable pulp inflammation model. Zymosan may be used to develop pulp inflammation model and study inflammatory response towards fungal antigens. Dental pulp expressed Dectin-1 receptor. OPN and TNF-α exhibited a similar expression pattern. CLINICAL RELEVANCE: Innate immunity of dental pulp is capable of detecting fungal pathogens.

Gene expression analysis of toll like receptor 2 and 4, Dectin-1, Osteopontin and inflammatory cytokines in human dental pulp ex-vivo.

BACKGROUND: Toll like receptors (TLR) 2 and 4 present on innate immune cells of the dental pulp detect cariogenic bacteria. Along with bacteria, C. albicans may also be present in dental caries. The presence of C. albicans can be detected by Dectin-1 a C type Lectin receptor. Expression of Dectin-1 in human pulpits has not been reported. Similarly, cytokines are released as a consequence of dental pulp inflammation caused by cariogenic bacteria. The T helper (Th) 1 inflammatory response leads to exacerbation of inflammation and its relationship with Osteopontin (OPN) is not known in pulp inflammation. OBJECTIVE: The aim of this study was to observe the expression of Dectin-1, TLR-2, OPN and pro-inflammatory cytokines in irreversibly inflamed human dental pulp and to observe relationship between Dectin-1/TLR-2 and OPN/Pro-inflammatory cytokines in the presence of appropriate controls. METHODS: A total of 28 subjects diagnosed with irreversible pulpitis were included in this ex-vivo study. Fifteen samples were subjected to standard hematoxylin and Eosin (H&E) and immunohistochemistry staining. Whereas, gene expression analysis was performed on 13 samples to observe mRNA expression of pro-inflammatory cytokines; tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1 beta (ß), IL-6 Dectin-1, OPN, TLR-2 and TLR-4. SPSS version 21 was used for statistical analysis. One way analysis of variance (ANOVA), Pearson correlation and Chi-square test were used at p ≤ 0.05. RESULTS: Gene expressions of Dectin-1, TLR-2 and TLR-4 were observed in all samples. Dectin-1 and TLR-2 expressions were significantly correlated (r = 0.5587, p = 0.0002). Similarly, OPN and TNF-α expression showed a significant correlation (r = 0.5860, p = 0001). The agreement between histologic and clinical diagnosis was 69.2% in the cases of irreversible pulpitis. CONCLUSION: Dectin-1 was expressed by inflamed human dental pulp. Dectin-1 and TLR-2 expression pattern was suggestive of a collaborative receptor response in inflamed pulp environment. OPN and TNF-α expressions showed a positive correlation indicating a possible relationship.

Effect of bisphosphonates on root resorption after tooth replantation - a systematic review.

BACKGROUND/AIM: Replantation of avulsed teeth may lead to root resorption. Bisphosphonates (BPs), a class of drugs of used to treat resorptive diseases of the bone such as osteoporosis and Paget's disease, have been observed to exert an antiresorptive effect on periodontal bone as well. The antiresorptive properties of BPs could prove them useful in preventing root resorption of replanted avulsed teeth. The aim of this systematic review was to analyze and summarize the currently available literature concerning the use of BPs in preventing root resorption of avulsed teeth. MATERIALS AND METHODS: PubMed/MEDLINE, Google Scholar, ISI Web of Knowledge, and Embase databases were searched using keywords 'bisphosphonate', 'replantation', and 'tooth'. Quality assessment of each study was carried out. In addition, general characteristics and outcomes of each study were summarized. RESULTS: After exclusion of 116 irrelevant articles, 10 animal studies were included in this review. The majority of the studies suggest that surface application of zoledronate or alendronate reduces root resorption of replanted teeth in animal models. Surface treatment with etidronate had no significant effect on root resorption, and intracanal etidronate accelerated resorption. CONCLUSION: Surface application of zoledronate and alendronate reduces root resorption of replanted teeth in animal models. However, the efficacy of intracanal usage of BPs is still debatable.

Correlation of ABH blood group antigens secretion with Helicobacter pylori infection in Pakistani patients.

OBJECTIVES: A and B blood group antigens are fucosylated carbohydrate present on human erythrocytes and body secretions. Their presence in body secretions depends on the expression of a dominant allele of secretor gene FUT2 and is correlated with susceptibility to various infectious and non-infectious diseases. We investigated the correlation of blood group and ABH antigen secretion with Helicobacter pylori infection and gastroduodenal symptoms and analysed the distribution of babA gene among ABH secretors and non-secretors. METHODS: Two hundred and ninety patients who underwent gastroduodenal endoscopy during 2011 to 2012 participated. Gastric biopsy, saliva and blood samples were obtained from every patient. Gastric biopsies were subjected to rapid urease test and PCR for the detection of H. pylori and babA gene. Blood grouping and ABH antigens secretions were determined by Lewis blood group phenotyping and haemagglutination inhibition test. RESULTS: 50.34% of patients were ABH antigen secretors and 45.51% non-secretors. Distribution analysis of blood group revealed that 40 blood group B, 67 blood group A 20 blood group O and 19 blood group AB patients secreted ABH antigens in saliva. Fifty-six blood group O, 19 blood group B, 32 blood group A and 17 blood group AB patients were non-secretors. Gastroduodenal complaints were common among non-secretors. Sixty-two percent of patients with a combination of duodenal ulcer and gastro-oesophageal reflux and 54% of patients with gastritis were non-secretors. Of 290 samples, 31.02% were positive for H. pylori. Thirty percent of these tested positive for babA gene; the majority belonged to non-secretor blood group O. CONCLUSIONS: Our results suggest that the infection of H. pylori is correlated with ABO blood groups and blood group antigens secretion in body fluids.