Mortality risk factors and fulminant sub-phenotype in anaerobic bacteremia: a 10-year retrospective, multicenter, observational cohort study.

PURPOSE: During the last decade, the incidence of anaerobic bacteremia (AB) has been increasing. Patients with AB may develop complex underlying diseases, which can occasionally be accompanied by fatal or fulminant outcomes. However, the risk factors for AB-related mortality remain unclear. Herein, we sought to elucidate the risk factors for AB-related mortality. METHODS: In this multicenter, retrospective, observational study, we enrolled patients with culture-proven AB from six tertiary hospitals in Japan, between January 2012 and December 2021. Data on patient and infection characteristics, laboratory findings, treatment, and outcome were collected, and their associations with mortality were analyzed. RESULTS: A total of 520 participants were included. The 30-day mortality in the study cohort was 14.0% (73 patients), and malignant tumors were frequently observed comorbidities in 48% of the entire cohort. Multivariable logistic regression analysis showed a Charlson comorbidity score of > 6, serum creatinine level of > 1.17 mg/dL, and hypotension to be independent risk factors for 30-day mortality in AB (odds ratios [ORs] 2.12, 2.25, and 5.12, respectively; p < 0.05), whereas drainage significantly reduced this risk (OR, 0.28; p < 0.0001). Twelve patients (2.3% of the whole cohort and 16.4% of the deceased patients) presented with extremely rapid progression leading to fatal outcome, consistent with "fulminant AB." CONCLUSIONS: This study identified acute circulatory dysfunction and performance of drainage as independent predictive factors for 30-day AB-related mortality and revealed the existence of a fulminant AB sub-phenotype. Our findings could serve as a practical guide to predict the clinical outcomes of AB.

The efficacy of eribulin mesylate for patients with cutaneous angiosarcoma previously treated with taxane: a multicentre prospective observational study.

BACKGROUND: Taxanes are the current first-line treatment for advanced cutaneous angiosarcoma (CAS) for patients who are considered difficult to treat with doxorubicin owing to advanced age or comorbidity. However, no effective second-line therapy for such patients has been established. METHODS: We designed a single-arm prospective observational study of eribulin mesylate (ERB) administered at a dose of 1·4 mg m-2 on days 1 and 8 in a 21-day cycle. Patients with advanced CAS who were previously treated with a taxane and were scheduled to begin ERB treatment were enrolled. The primary endpoint was overall survival (OS) and the secondary endpoints were response rate (RR), progression-free survival (PFS) and toxicity assessment. RESULTS: We enrolled a total of 25 patients. The median OS and PFS were 8·6 months and 3·0 months, respectively. The best overall RR was 20% (five of 25). In total, 16 grade 3/4 severe adverse events (SAEs) occurred; however, all patients recovered. Patients who achieved partial response or stable disease as best response had longer OS than those with progressive disease (median OS not reached and 3·3 months, respectively; P < 0·001). Patients who did not experience SAEs showed longer OS than those who did (median OS 18·8 months and 7·5 months, respectively; P < 0·05). Patients with distant metastasis had shorter median OS than those with locoregional disease, but without statistically significant difference. CONCLUSIONS: ERB showed a promising RR and is a potential candidate for second-line treatment for patients with CAS, after treatment with taxanes. However, owing to the occurrence of SAEs in over half of the participants, caution should be exercised regarding ERB use in elderly patients. What is already known about this topic? Taxanes are the current first-line treatment for patients with advanced cutaneous angiosarcoma (CAS) who are considered difficult to treat with doxorubicin owing to advanced age or comorbidity. No effective therapy for taxane-resistant CAS has been established thus far. Eribulin suppresses microtubule polymerization and elicits an antitumour effect similar to that of taxanes. What does this study add? In our single-arm prospective observational study to evaluate the efficacy of eribulin for treating patients with advanced CAS who previously received taxanes, the median overall survival and progression-free survival were 8·6 and 3·0 months, respectively. Response rates at weeks 7, 13 and 25 were 20%, 17% and 14%, respectively. Although 16 grade 3/4 severe adverse events occurred, all patients recovered. Eribulin showed a promising response rate and is a potential candidate for second-line treatment in CAS after taxane treatment. Linked Comment: Smrke and Benson. Br J Dermatol 2020; 183:797-798.

Three patients with advanced cutaneous angiosarcoma treated with eribulin: investigation of serum soluble CD163 and chemokine (C-X-C motif) ligand 10 as possible biomarkers predicting the biological behaviour of angiosarcoma.

Cutaneous angiosarcoma (CAS) is a highly aggressive vascular tumour that recurs locally and metastasizes early. Although chemoradiotherapy with taxanes shows a high response rate with prolonged survival, second-line therapy for advanced CAS remains contentious. This report describes three patients with advanced CAS treated with eribulin. In addition, we investigated serum soluble (s)CD163, chemokine (C-X-C motif) ligand 10 (CXCL10) and chemokine (C-C motif) ligand 2 levels at several time points of tumour progression in these patients, revealing serum levels of sCD163 and CXCL10 as potential biomarkers for progression of CAS.

Androgen induces G3BP2 and SUMO-mediated p53 nuclear export in prostate cancer.

The androgen receptor (AR) has a central role in prostate cancer progression, particularly treatment-resistance disease including castration-resistant prostate cancer. Loss of the p53 tumor suppressor, a nuclear transcription factor, is also known to contribute to prostate malignancy. Here we report that p53 is translocated to the cytoplasm by androgen-mediated induction of G3BP2, a newly described direct target gene of AR. G3BP2 induces both cell cycle progression and blocks apoptosis. Translocation of p53 is regulated by androgen-dependent sumoylation mediated by the G3BP2-interacting SUMO-E3 ligase, RanBP2. G3BP2 knockdown results in reduced tumor growth and increased nuclear p53 accumulation in mouse xenograft models of prostate cancer with or without long-term androgen deprivation. Moreover, strong cytoplasmic p53 localization is correlated clinically with elevated G3BP2 expression and predicts poor prognosis and disease progression to the hormone-refractory state. Our findings reveal a new AR-mediated mechanism of p53 inhibition that promotes treatment-resistant prostate cancer.

Der f 35: An MD-2-like house dust mite allergen that cross-reacts with Der f 2 and Pso o 2.

BACKGROUND: Dermatophagoides farinae is a source of airborne house dust mite (HDM) allergens. We elucidated IgE-reactive allergens from D. farinae by two-dimensional immunoblotting-based allergenome analysis, and identified one new allergen, named Der f 35, that possesses IgE-binding capacity comparable to that of Der f 2. The aim of this study was to clarify the allergenic capacity of new HDM allergen Der f 35. METHODS: We cloned der f 35 from D. farinae mRNA and produced recombinant Der f 35 in Escherichia coli. The IgE-binding capacity of Der f 35 and its cross-reactivity with group 2 allergens from D. farinae and Psoroptes ovis were determined by enzyme-linked immunosorbent assay (ELISA) and ELISA inhibition assays, respectively. RESULTS: The deduced amino acid sequence for der f 35, which possesses the MD-2-related lipid-recognition domain, showed higher identity with group 2 allergens from P. ovis (61.5%) and Blomia tropicalis (50.7%) than with Der f 2 (40.8%). Der f 35 showed IgE-binding frequencies of 77.5% (31/40) for the native form upon allergenome analysis and 51.4% (18/35) for recombinant structure by ELISA. Der f 35 showed cross-reactivity with Der f 2 and Pso o 2 in reaction with HDM-allergic patients' IgE by ELISA inhibition assay. CONCLUSION: Der f 35 is a candidate major allergen from D. farinae, which is more similar to group 2 allergens from sheep scab mite and storage mites. Der f 35 could be responsible for the cross-reactivity among group 2 mite allergens.

Photoinduced electron transfer in layer-by-layer thin solid films containing cobalt oxide nanosheets, porphyrin, and methyl viologen.

The well-known layer-by-layer (LbL) method can be used to prepare solid thin films with a controlled electron transfer direction by appropriately stacking metal oxide nanosheets and functional organic ions. In this study, we prepared thin solid films consisting of cobalt oxide nanosheets (CoNSs) as the electron transfer medium, α,ß,γ,δ-tetrakis(1-methylpyridinium-4-yl)porphyrin (TMPyP) as the electron donor, and 1,1'-dimethyl-4,4'-bipyridinium or methyl viologen (MV) as the electron acceptor. We investigated the photoinduced electron transfer phenomenon in these films by irradiating them with 450 nm light. Irradiating the LbL thin solid films prepared with the CoNS/TMPyP/CoNS/MV/CoNS sequence under reduced pressure led to the production of a one-electron reduction compound of MV. Hence, photoinduced electron transfer from TMPyP to MV bound to CoNSs occurred in these LbL thin solid films. However, the conduction band of CoNSs, as determined by the photoabsorption spectral and photoelectrochemical measurements, was much higher than the lowest unoccupied molecular orbital level of TMPyP. Our findings indicate that the observed equipotential photoinduced electron transfer was caused by the metallic electron conductivity of CoNSs, which show a unique charge arrangement of Co3+ and Co4+. Moreover, it was also found that the observed photoinduced charge separation state has a longer life-time (>5 h) under the reduced conditions.

Ceramide synthase 4 is highly expressed in involved skin of patients with atopic dermatitis.

BACKGROUND: Ceramide is a crucial lipid in the stratum corneum (SC) which maintains the barrier function and hydration of the skin. In atopic dermatitis (AD) patients who have defective skin barrier function, ceramide levels are altered. We previously reported that although the amount of total ceramide was lower in involved skin compared with uninvolved skin of AD patients and with healthy control skin, the amounts of smaller ceramide species of Cer[NS] (<40 total carbons, which are total carbons of both sphingoid base and amide-linked fatty acid), especially Cer[NS] with 34 total carbons (C34-Cer[NS]), were higher. However, the enzyme(s) that produces the higher levels of smaller ceramide species in involved skin of AD patients was unclear. OBJECTIVE: To identify the enzyme(s) that produces higher levels of smaller ceramide species of Cer[NS] in the involved skin of AD patients. METHODS: Eight female Caucasian subjects who were diagnosed with AD on their arms (age range: 21-45 years) were enroled in this study. We compared ceramide levels in the SC and the expression levels of enzymes involved in ceramide metabolism using real-time PCR and immunohistochemistry between involved and uninvolved skin of AD patients. RESULTS: Level of mRNA encoding ceramide synthase 4 (CERS4), which is one of the enzymes that synthesize ceramide from a sphingoid base and an amide-linked fatty acid, was significantly higher in involved skin than in uninvolved skin (P < 0.01). Additionally, the protein expression level of CERS4 in the epidermis was also higher in involved skin compared with uninvolved skin. The expression level of CERS4 correlated with the amount of C34-Cer[NS] (P < 0.01) and the skin hydration value (P < 0.05). CONCLUSIONS: The elevated expression level of CERS4 contributes to the increase of C34-Cer[NS] and the impaired SC barrier function in involved skin of AD patients.

Possible mechanisms of the crosstalk between Langerhans cells and regulatory T cells in extramammary Paget disease by receptor activator of nuclear factor kappa B (RANK) ligand/RANK pathways.

BACKGROUND: Extramammary Paget disease (EMPD) is a skin adenocarcinoma of apocrine gland origin, in which Paget cells express receptor activator of nuclear factor kappa B (RANK) ligand (RANKL) and matrix metalloproteinase (MMP)-7, and release soluble (s)RANKL into the tumour microenvironment. We previously reported that about 60% of the RANK+ cells among the stromal cells are M2 macrophages, but the identity of the remaining population of RANK+ cells is still unknown. OBJECTIVES: To investigate the unknown subpopulation of RANK-expressing cells in EMPD. METHODS: The main population of RANK-expressing cells in the epidermis was composed of epidermal Langerhans cells (LCs). To explore the effects of RANKL on LCs, we stimulated LCs generated from human CD34+ hematopoietic progenitor cells with graded concentrations of sRANKL. To further examine the correlation between LCs and regulatory T cells (Tregs) in EMPD, we employed immunohistochemical staining. RESULTS: sRANKL stimulation was shown to augment the production of C-C motif chemokine ligand 17 (CCL17) from LCs. We additionally demonstrated CCL17 expression by CD1a+ LCs in EMPD in an immunofluorescence study. Spearman's rank correlation test confirmed a correlation between the number of LCs and the number of Foxp3+ Tregs in the lesional skin of invasive EMPD. In addition, the numbers of Foxp3+ Tregs in the sentinel lymph nodes of metastatic EMPD were significantly higher than those of metastatic melanoma, which did not express RANKL. CONCLUSIONS: The findings suggest that the RANKL/RANK pathway in EMPD might contribute to the recruitment of Tregs and to maintenance of the tumour microenvironment.

Changes in hydration of the stratum corneum are the most suitable indicator to evaluate the irritation of surfactants on the skin.

BACKGROUND/PURPOSE: Irritancy levels of surfactants on human skin have not been clarified completely. The relationships between skin damage and changes of skin properties caused by various surfactants were investigated using non-invasive measurements. METHODS: Aqueous solutions of seven kinds of anionic, non-ionic, and amphoteric surfactants were exposed to the inside of forearm skin of 20 human subjects in two separate studies using the cup method. Hydration of the stratum corneum (SC), transepidermal water loss (TEWL), pH, skin surface roughness, and contents of the SC were measured before and after one exposure and after five and nine consecutive exposures to various surfactants. The discontinuation ratio of subjects for testing in each surfactant was determined by skin irritation symptoms and was defined as the degree of skin damage. RESULTS: Significant changes were observed only in hydration, TEWL, and natural moisturizing factors (NMF) content in the SC following surfactant exposure. A significant correlation was observed between the discontinuation ratio of each surfactant and the changes of hydration, TEWL, and NMF. Especially, the change of SC hydration showed an excellent correlation with the discontinuation ratio both for single (r = 0.942, P < 0.001) and for chronic exposures (r = 0.934, P < 0.001). CONCLUSION: Our results indicate that the change of hydration of the SC is equivalent to the skin damage caused by surfactants, and therefore is the most suitable indicator to evaluate the irritation of surfactants on the skin.

Targeting Oct1 genomic function inhibits androgen receptor signaling and castration-resistant prostate cancer growth.

Androgen receptor (AR) functions as a ligand-dependent transcription factor to regulate its downstream signaling for prostate cancer progression. AR complex formation by multiple transcription factors is important for enhancer activity and transcriptional regulation. However, the significance of such collaborative transcription factors has not been fully understood. In this study, we show that Oct1, an AR collaborative factor, coordinates genome-wide AR signaling for prostate cancer growth. Using global analysis by chromatin immunoprecipitation sequencing (ChIP-seq), we found that Oct1 is recruited to AR-binding enhancer/promoter regions and facilitates androgen signaling. Moreover, a major target of AR/Oct1 complex, acyl-CoA synthetase 3 (ACSL3), contributes to tumor growth in nude mice, and its high expression is associated with poor prognosis in prostate cancer patients. Next, we examined the therapeutic effects of pyrrole-imidazole polyamides that target the Oct1-binding sequence identified in the center of the ACSL3 AR-binding site. We observed that treatment with Oct1 polyamide severely blocked the Oct1 binding at the ACSL3 enhancer responsible for its transcriptional activity and ACSL3 induction. In addition, Oct1 polyamides suppressed castration-resistant tumor growth and specifically repressed global Oct1 chromatin association and androgen signaling in prostate cancer cells, with few nonspecific effects on basal promoter activity. Thus, targeting Oct1 binding could be a novel therapeutic strategy for AR-activated castration-resistant prostate cancer.

Five-year clinical results for treatment of intrabony defects with EMD, guided tissue regeneration and open-flap debridement: a case series.

BACKGROUND AND OBJECTIVE: Although regenerative periodontal surgery with EMD or guided tissue regeneration (GTR) has been shown to enhance periodontal regeneration, there are limited data on the long-term results following these treatment modalities. The purpose of the present study was to investigate the long-term clinical outcomes in intrabony defects following regenerative periodontal surgery with EMD or GTR compared with open-flap debridement (OFD). MATERIAL AND METHODS: Data from 40 subjects (44 teeth), with no history of smoking or systemic diseases that could interfere with periodontal disease and who received one of three surgical procedures (EMD, GTR or OFD) for two- or three-wall intrabony defects, were analyzed. Postoperative reduction in probing pocket depth, gain in clinical attachment level, gingival recession and percentage bone fill were compared at 1, 3 and 5 years. RESULTS: Reduction in probing pocket depth after GTR was significantly higher than after OFD at 1 and 3 years postoperatively, but there was no difference between the groups at 5 years. The gains in clinical attachment level for EMD (at 3 and 5 years) and for GTR (at 1, 3 and 5 years) were significantly greater than for OFD. Gingival recession after treatment with EMD and GTR showed a tendency toward positive results, whereas no such tendency was observed for OFD. Postoperative percentage bone fill for EMD and GTR was significantly greater than for OFD at 3 and 5 years. CONCLUSIONS: This is a retrospective study and an exploratory report with a high risk of bias. Within the limits of the current study, it may be concluded that superior gains in clinical attachment level and improved percentage bone fill can be obtained with EMD and GTR when compared with OFD, and these can be maintained over a period of 5 years.

Severe veno-occlusive disease/sinusoidal obstruction syndrome after deceased-donor and living-donor liver transplantation.

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) occurring after liver transplantation is a relatively rare complication but it often takes a life-threatening course. However, the detailed etiology and mechanism of VOD/SOS after liver transplantation (LT) remains unclear. We report two cases with rapidly progressive VOD/SOS after ABO-identical LT resistant to various therapies. In case 1, in which the patient underwent deceased-donor LT, the first episode of acute allograft rejection was triggered VOD/SOS, and the presence of donor non-specific anti-HLA antibodies was confirmed. The recipient died with graft failure on day 46 after transplantation. Case 2, in which the patient underwent living-donor LT from the mother, had neither rejection nor mechanical venous obstruction, but condition of the patient rapidly worsened and he died on day 13 after transplantation. This recipient's direct cross-match test for the donor's B lymphocyte was strongly positive, but that for T lymphocyte was negative. In both cases, neither stenosis of hepatic vein outflow tract nor C4d deposition in post-transplantation liver biopsy specimens and autopsy specimen was found. On the other hand, in both cases, the patient was transfusion unresponsive thrombocytopenia and hyperbilirubinemia persisted postoperatively, and glycoprotein Ⅰ bα was strongly stained in the neighboring centrilobular area (zone 3), especially in the space of Disse, and platelet phagocytosis was observed in Kupffer cells and hepatocytes around zone 3 such as clinical xenotransplantation of the liver in post-transplantation liver biopsy specimens. From the viewpoint of graft injury, VOD/SOS was considered that sustained sinusoidal endothelial cells injury resulted in bleeding in the space of Disse and led to around centrilobular hemorrhagic necrosis, and the fundamental cause was damage around centrilobular area including sinusoid by acute cellular rejection, antibody-mediated rejection or ischemic reperfusion injury. The extrasinusoidal platelet activation, aggregation, and phagocytosis of platelets were some of the main reasons for VOD/SOS and transfusion-resistant thrombocytopenia.

Age-related changes of stratum corneum functions of skin on the trunk and the limbs.

BACKGROUND/AIMS: Despite our understanding that the care of back and buttock skin is important for elderly nursing patients, the stratum corneum (SC) functions of the skin on the trunk of elderly patients have not been well investigated. METHODS: Overall, 41 elderly subjects (average age: 75.9 years, 20 male and 21 female) and 20 middle-aged subjects (average age: 41.3 years, 10 male and 10 female) residing in Tokyo were recruited. Hydration of the SC, transepidermal water loss (TEWL), skin surface pH, total bacteria and inflammatory cytokines in the SC of skin on the buttocks, back, lower leg and inner forearm were measured. RESULTS AND CONCLUSION: The hydration of the SC decreased only on the lower leg with age. TEWL showed no change with age at any site. The pH was significantly higher in elderly skin than in middle-aged skin at all sites. The number of total bacteria on the forearm and back increased with age. The ratio of interleukin-1α (IL-1α) and IL-1α receptor antagonist was only higher on the middle-aged forearm compared to the elderly. No remarkable gender difference was found in these parameters without pH values. We clarified that most of the SC functional parameters change with age on both the trunk and the limbs in a similar manner, suggesting that the limbs are acceptable sites to estimate the SC functions of the trunk of elderly patients. Our study may be useful as basic data for future work to maintain the SC function of elderly patients.

Sialyl-glycoconjugates in cholesterol-rich microdomains of P388 cells are the triggers for apoptosis induced by Rana catesbeiana oocyte ribonuclease.

SBL/RC-RNase was originally isolated from frog (Rana catesbeiana) oocytes and purified as a novel sialic acid-binding lectin (SBL) that displayed strong anti-cancer activity. SBL was later shown to be identical to a ribonuclease (RC-RNase) from oocytes of the same species. The administration of SBL/RC-RNase induced apoptosis (with nuclear condensation and DNA fragmentation) in mouse leukemia P388 cells but did not kill umbilical vein endothelial or fibroblast cells derived from normal tissues. The cytotoxic activity of SBL/RC-RNase was inhibited by desialylation of P388 cells and/or the co-presence of free bovine submaxillary mucin. FACS analysis showed that SBL/RC-RNase was incorporated into cells after attachment to cholesterol-rich microdomains. Addition of the cholesterol remover methyl-ß-cyclodextrin reduced SBL/RC-RNase-induced apoptosis. Apoptosis occurred through the caspase-3 pathway following activation of caspase-8 by SBL/RC-RNase. A heat shock cognate protein (Hsc70) and a heat shock protein (Hsp70) (each 70 kDa) on the cell membrane were shown to bind to SBL/RC-RNase by mass spectrometric and flow cytometric analyses. Quercetin, an inhibitor of Hsc70 and Hsp70, significantly reduced SBL/RC-RNase-induced apoptosis. Taken together, our findings suggest that sialyl-glycoconjugates present in cholesterol-rich microdomains form complexes with Hsc70 or Hsp70 that act as triggers for SBL/RC-RNase to induce apoptosis through a pathway involving the activation of caspase-3 and caspase-8.

Thoracoscopic esophagectomy with extended lymph node dissection in the left lateral position: technical feasibility and oncologic outcomes.

The aim of this study was to estimate the technical and oncologic feasibility of video-assisted thoracoscopic radical esophagectomy (VATS) in the left lateral position. From January 2003 to December 2011, 132 patients with esophageal cancer underwent VATS. The mean duration of the thoracic procedure and the entire procedure was 294 ± 88 and 623 ± 123 minutes, respectively. Mean blood loss during the thoracic procedure and the entire procedure was 313 ± 577 and 657 ± 719 g, respectively. The mean number of dissected thoracic lymph nodes was 32.6 ± 12.9. There were four in-hospital deaths (3.0%); two patients (1.5%) died of acute respiratory distress syndrome and two patients (1.5%) died of tumor progression. Postoperative unilateral or bilateral recurrent laryngeal nerve (RLN) palsy, or pneumonia was found in 33 (25.0%), 21 (15.9%), and 27(20.5%) patients, respectively. The patients were divided into the first 66 patients who underwent VATS (Group 1) and the subsequent 66 patients (Group 2). The numbers of cases who underwent neoadjuvant or induction chemotherapy for T4 tumor and intrathoracic anastomosis were higher in Group 2 than in Group 1. The duration of the procedure, amount of blood loss, and the number of dissected thoracic lymph nodes were not different between the two groups. The total number of dissected lymph nodes was higher in Group 2 than in Group 1 (72.6 ± 27.8 vs. 62.6 ± 21.6, P = 0.023). The rate of bilateral RLN palsy was less in Group 2 than in Group 1 (7.6% vs. 24.2%, P = 0.042). The mean follow-up period was 38.7 months. Primary recurrence consisted of hematogenous, lymphatic, peritoneal dissemination, pleural dissemination, and locoregional in 15 (11.3%), 20 (15.1%), 3 (2.3%), 4 (3.0%), and 5 patients (3.8%), respectively. The rate of regional lymph node recurrence within the dissection field was only 4.5%. The prognosis of patients with lymph node metastasis was significantly poorer than that of patients without lymph node metastasis. However, the prognosis of the 11 cases that had metastasis only around RLNs was similar to that of node-negative cases. Thirteen patients with pathological remnant tumor (R1 or R2) did not survive longer than 5 years at present. The overall 5-year survival rate of stage I, II, and III disease after curative VATS was 82.2%, 77.0%, and 52.3%, respectively. Expansion of VATS criteria for patients after induction chemotherapy for T4 tumor or thoracoscopic anastomosis did not adversely affect the surgical results by experience. Although the VATS procedure is accompanied by a certain degree of morbidity including RLN palsy and pulmonary complications, VATS has an excellent locoregional control effect. In addition, the favorable survival after VATS shows that the procedure is oncologically feasible.

Follicular dendritic cell-secreted protein is decreased in experimental periodontitis concurrently with the increase of interleukin-17 expression and the Rankl/Opg mRNA ratio.

BACKGROUND AND OBJECTIVE: T-helper type 17 (Th17) cells produce interleukin-17 (IL-17) and help to protect against inflammation and infection in periodontal disease. Furthermore, while follicular dendritic cell-secreted protein (FDC-SP) may be involved in the inflammation of periodontal tissue, the biological role of FDP-SP in periodontal disease is still unknown. The purpose of the present study was to clarify the expression of IL-17 and FDC-SP in experimental periodontitis in rats. MATERIAL AND METHODS: Seven-week-old male Wistar rats were divided into baseline control, sham and test groups. Experimental periodontitis was induced by placing a ligature in the mesiopalatal area, and untreated rats served as a baseline control group. Morphological changes in alveolar bone were investigated 7, 14 and 28 d after treatment. Expression of the Rankl, osteoprotegerin (Opg) and Il17 genes was analyzed 5 and 7 d after the induction of experimental periodontitis. RESULTS: Alveolar bone resorption progressed in the test group for 7 d, but not thereafter. At 5 d after the induction of periodontitis, the Rankl/Opg mRNA ratio and the expression of IL-17 in the test group were significantly increased compared with the respective values in the baseline control group; however, there were no significant differences between the test and control groups at 7 d. The expression of FDC-SP was significantly decreased in the test group compared with the baseline control group at 5 and 7 d after the induction of periodontitis, and this value had returned to normal levels at 14 and 28 d. CONCLUSION: These results suggest that both IL-17 and FDC-SP could be involved in the inflammatory response, and FDC-SP in the junctional epithelium might play an important role in the Th17 cell-related immune response.