Peri-implant phenotype, calprotectin and MMP-8 levels in cases diagnosed with peri-implant disease.

OBJECTIVES: The purpose of this prospective cohort study is to evaluate the effect of peri-implant phenotype (PPh) on the severity of peri-implant diseases and the results of non-surgical mechanical treatment (NSMT), along with calprotectin (CLP) and MMP-8(matrix metalloproteinase-8) levels. MATERIALS AND METHODS: 77 implants from 39 patients were included. The implants were categorized Group-1(peri-implant mucositis), Group-2(peri-implantitis).Baseline (0. Month-PrT) clinical parameters (PD, GI, PI, BOP, CAL) and radiographic bone loss were documented, and peri-implant crevicular fluid (PICF) samples were collected. Various intruments and methodologies were employed to assess PPh components (mucosa thickness, supracrestal tissue height, keratinized mucosa) and peri-implant attached mucosa (AM). NSMT was applied to diseased implant sites. All clinical parameters were reassessed again by taking PICF samples at the 6th month-after treatment (PT). In PICF samples obtained from both groups, MMP-8 and CLP levels were evaluated using the ELISA test. RESULTS: PrT-PD,PrT-GI,PrT-CAL and PrT-BOP percentage values in Group-2 were significantly higher than Group-1.PrT-PD,PrTPI scores are significantly higher in thin biotype implants. All components of the PPh and AM were significantly lower in thin biotype. Intra-group time-dependent changes of MMP-8 and CLP were significant in both groups (p < 0.05). When the relationship between thin and thick biotype and biochemical parameters was evaluated, the change in PrT-PT didn't show a significant difference (p > 0.05). CONCLUSIONS: PPh plays a role in influencing the severity of peri-implant diseases. However, the impact of phenotype on NSMT outcomes was similar in both groups. CLINICAL RELEVANCE: The PPh should be considered when planning implant surgery.

Analysis of the association between salivary proteins and oral mucositis in patients with head and neck cancer undergoing IMRT: a longitudinal study.

INTRODUCTION: This longitudinal study assessed the association between salivary protein composition and the clinical onset/severity of oral mucositis (OM) in patients with head and neck tumours treated with intensity-modulated-radiotherapy (IMRT). METHODS: Saliva samples/clinical data were obtained from 40 head and neck cancer patients treated at Guy's Hospital before -IMRT(T0) and after-IMRT (T1 = 6 m, T2 = 12 m) (ethics approval/consent). Salivary flow rate, total protein concentration, and secretion rate were determined from saliva samples and compared with pre-treatment values. OM was assessed, total/specific salivary proteins, including mucin 5B and 7, IgA, cystatin-S, albumin, and α-amylase, were quantified. RESULTS: 95% patients experienced OM during IMRT, with 33 subjects reaching grade 2&3. At T1, there was a significant reduction in salivary flow rate, total protein secretion rate, α-amylase and cystatin-S compared to baseline. Remarkably IMRT did not significantly alter mucin 5B and 7, or the IgA secretion rate at any time point. At T1, all the analyzed proteins were associated with the OM outcomes. In addition, there was a significant inverse correlation between IgA concentration at T0 and the severity of OM during IMRT. CONCLUSION: This study revealed significant associations between several salivary proteins and OM in patients with head and neck cancer undergoing IMRT. Further longitudinal studies are needed to confirm these results. CLINICAL SIGNIFICANCE: The study contributes to the understanding of certain salivary proteins association with OM. This could be the first step towards identifying potential salivary markers that could offer perspectives for personalized medicine approaches to improve their quality of life (QoL). RESEARCH QUESTION: What is the association between salivary proteins and the occurrence and severity of OM in head and neck cancer patients? AIM: To assess the association between salivary protein composition with the clinical onset/severity of oral mucositis (OM) in head and neck cancer patients treated with intensity modulated radiotherapy. NULL HYPOTHESIS: There is no association between salivary proteins and onset/severity of OM in HNC patients.

Sildenafil improves radiation-induced oral mucositis by attenuating oxidative stress, NF-κB, ERK and JNK signalling pathways.

Radiation-induced oral mucositis is a common and dose-limiting complication of head and neck radiotherapy with no effective treatment. Previous studies revealed that sildenafil, a phosphodiesterase 5 inhibitor, has anti-inflammatory and anti-cancer effects. In this study, we investigated the effect of sildenafil on radiation-induced mucositis in rats. Two doses of radiation (8 and 26 Gy X-ray) were used to induce low-grade and high-grade oral mucositis, separately. A control group and three groups of sildenafil citrate-treated rats (5, 10, and 40 mg/kg/day) were used for each dose of radiation. Radiation increased MDA and activated NF-κB, ERK and JNK signalling pathways. Sildenafil significantly decreased MDA level, nitric oxide (NO) level, IL1ß, IL6 and TNF-α. The most effective dose of sildenafil was 40 mg/kg/day in this study. Sildenafil also significantly inhibited NF-κB, ERK and JNK signalling pathways and increased bcl2/bax ratio. In addition, high-dose radiation severely destructed the mucosal layer in histopathology and led to mucosal cell apoptosis in the TUNEL assay. Sildenafil significantly improved mucosal structure and decreased inflammatory cell infiltration after exposure to high-dose radiation and reduced apoptosis in the TUNEL assay. These findings show that sildenafil can improve radiation-induced oral mucositis and decrease the apoptosis of mucosal cells via attenuation of inflammation and oxidative stress.

Salivary antioxidant enzymes associated with oral toxicity in haematopoietic cell transplantation: An observational study.

BACKGROUND: In haematopoietic cell transplantation (HCT), oral mucositis and xerostomia are related to conditioning-related oxidative stress. The role of salivary antioxidant enzymes in oral toxicity is poorly described. The aim of this study was to verify the association between salivary antioxidant enzymes and oral mucositis and xerostomia in HCT. DESIGN: Saliva from autologous and allogeneic HCT patients (n = 77) was selected before conditioning (T0), during the neutropenia period (T1) and after marrow engraftment (T2). Salivary flow, total salivary proteins, and superoxide dismutase, catalase and glutathione reductase activities were measured. RESULTS: There were no significant differences in salivary flow, total salivary proteins and catalase at the three HCT time points. Glutathione reductase levels were reduced at T1 compared to T0 (P = .013) and T2 (P = .001). Superoxide dismutase levels were increased from T0 to T2 (P = .013). Neither of these enzymes was associated with oral mucositis. Increased superoxide dismutase levels were associated with xerostomia frequency. Levels of this enzyme also showed significant correlation with days of xerostomia in T2 (ρ = .40, P = .002). CONCLUSIONS: Salivary antioxidant enzymes changed before and during early periods after HCT. The increase in salivary superoxide dismutase suggested partial activation of the salivary antioxidant system and was associated with xerostomia.

Treatment for Oral Mucositis-Current Options and an Update of Small Molecules Under Development.

OPINION STATEMENT: Despite its history as one of the most impactful toxicities associated with cytotoxic cancer therapy, oral mucositis (OM) remains an unmet clinical need which affects hundreds of thousands of patients. Descriptions of its complex pathogenesis have provided mechanistic targets which are being exploited to develop an effective therapeutic intervention. Favorable results of recently completed clinical trials in which agents focused on interrupting the early stages of the mucositis biological cascade were assessed provide reason for optimism, not only for oral mucositis but also for halo indications which share its pathobiogenesis.

Photobiomodulation modulates inflammation and oral microbiome: a pilot study.

INTRODUCTION: Oral mucositis (OM) is a severe side effect in patients undergoing anticancer therapies, which negatively impacts on their quality of life often leading to either the interruption of the therapy. Photobiomodulation (PBM) is emerging as an effective strategy allowing a faster wound healing. OBJECTIVES: This pilot study aims at verifying whether PBM modulates the inflammatory response in patients and its effect on the oral microbiome composition. MATERIALS AND METHODS: Buccal swabs were collected from four patients affected by OM, both on ulcerated and clinically healthy areas, before and on the last day of PBM therapy, as well as on the first day after treatment discontinuation. The concentration of 38 cytokines and the composition of oral microbiome were measured. RESULTS: Most of the pro-inflammatory cytokines were reduced, whereas anti-inflammatory cytokines resulted up-regulated by PBM. In addition, PBM influenced the composition of oral microbiome, by decreasing the amount of pathogenic species and promoting the growth of commensal bacteria. These changes were even more evident when separately analysing patients who clinically responded to PBM and the only patient who did not respond. CONCLUSIONS: PBM reduces inflammatory burden in patients affected by OM and positively influences the composition of the oral microbiome.

Exploring the role of oral microorganisms in the pathogenesis of mucositis by assessing their impact on metabolic activity and reproductive capacity of epithelial cells in vitro.

PURPOSE: Clinical and in vitro studies showed selected oral microorganisms to be related to delayed wound healing and ulcerative oral mucositis. However, it is not known whether this effect is due to reduced metabolism and/or the reduced reproductive capacity of epithelial cells. Therefore, we studied the influence of the oral microorganisms Porphyromonas gingivalis, Candida glabrata, and Candida kefyr on cell metabolism and reproductive capacity of oral epithelial cells, aimed to further unravel the pathogenesis of oral mucositis. METHODS: Oral epithelial cells were exposed to different concentrations of P. gingivalis, C. glabrata, and C. kefyr as mono-infections or mixed together. An MTT assay was performed to determine the effect on cell metabolism. A clonogenic assay was used to study the effect on the reproductive capacity of oral epithelial cells. RESULTS: The metabolism of oral epithelial cells was reduced when the microorganisms were present in high concentrations: P. gingivalis at a multiplicity of infection (MOI) of 1000 and the Candida spp. at MOI 100. No statistical difference was observed in the ability of a single epithelial cell to grow into a colony of cells between control and P. gingivalis, C. glabrata, and C. kefyr, independent of the concentrations and combinations used. CONCLUSION: P. gingivalis, C. glabrata, and C. kefyr lowered the metabolic activity of oral epithelial cells in high concentrations, yet they did not influence the reproductive capacity of epithelial cells. Their impact on ulcerative oral mucositis is likely due to an effect on the migration, proliferation, and metabolism of epithelial cells.

The Management of Pediatric Oncology Inpatients With Oral Mucositis.

The purpose of the study was to investigate the management of chemotherapy-induced oral mucositis (OM) in pediatric patients. A total of 68 separate episodes of OM were assessed in 47 children who had received chemotherapy. The severity of the child's OM was assessed using 2 scales, and relevant clinical information was collected. The mean onset time of OM was 8.4 days (±4.0), with a median duration of 7.0 days (4.0, 10.5), with median admission of 7.0 days (4.5, 13.5). The overall adherence to an oral health protocol was 59%, which decreased with more severe OM. A third of patients used chlorhexidine mouthwash only, which was used in preference in cases of severe OM. Almost all patients had some systemic analgesia administered, with a significant increase in patient-controlled analgesia/nurse-controlled analgesia and intravenous ketamine in severe cases. Various types of prophylaxis/treatment of secondary infections and supportive care were associated with the severity of OM. The management of OM in children is important to limit its burden. An oral care protocol was recommended. Chlorhexidine mouthwash can maintain some form of oral care when brushing becomes too uncomfortable in severe OM. Pain management is important for the management of OM, and its intensity increases with increasing severity of OM.

Protective effect of angiotensin II receptor blocker against oxidative stress and inflammation in an oral mucositis experimental model.

BACKGROUND: The aim of this study was to evaluate the effect of olmesartan medoxomil (Olme), an angiotensin II receptor antagonist, on oral mucositis (OM) experimental model. METHODS: Oral mucositis was induced in hamsters with 5-fluorouracil (5-FU; 60 mg/kg day 1 and 40 mg/kg day 2). Animals (n = 10/group) were pretreated with oral Olme (1, 5, or 10 mg/kg) or vehicle 30 minutes before 5-FU injection and daily, until day 10. Cheek pouch samples were subjected to histopathological and immunostaining analysis of IL-1ß, TNF-α, IL-10, TGF-ß, macrophage migration inhibitory factor (MIF), SOD, MMP-2 and FGF-2. In addition, IL-1ß and TNF-α levels were evaluated by ELISA. Myeloperoxidase activity (MPO), glutathione (GSH) and malondialdehyde (MDA) levels were investigated by spectroscopic UV/VIS analysis. Reverse transcriptase polymerase chain reactions (RT-PCRs) were used to quantify the expression of IL-1ß, TNF-α, NF-κBp65, MKP1 and ACE2. Inducible nitric oxide synthase (iNOS) and extracellular regulated kinase (ERK)1/2 protein levels were analysed by Western blot. RESULTS: Treatment with 10 mg/kg Olme reduced ulceration, inflammatory cell infiltration, MPO activity, MDA levels, iNOS and ERK1/2 proteins levels, MIF expression and TNF-α and IL-1ß of levels and gene expression. These findings were associated with a significant increase in the immunostaining of IL-10, FGF-2 and TGF-ß. In addition, gene expression of IL-1ß, TNF-α, NF-κBp65 MKP1 and ACE2 was decreased. CONCLUSION: Olmesartan at a dose of 10 mg/kg prevented the mucosal damage and inflammation associated with 5-FU-induced OM, increasing granulation and tissue repair.

Early salivary changes in multiple myeloma patients undergoing autologous HSCT.

OBJECTIVE: One explorative observational study in two parts was performed to examine early salivary changes in relation to oral mucositis (OM) in multiple myeloma patients treated with high-dose melphalan and autologous haematopoietic stem cell transplantation (HSCT). As cryotherapy was introduced after part A as regular care, its effect on OM could be evaluated. METHODS: Unstimulated whole-mouth saliva (UWS) and stimulated whole-mouth saliva (SWS) were collected, and OM was scored with the Oral Mucositis Nursing Instrument (OMNI) at days -3, 0, 4, 7, 11 and 14 after HSCT. Salivary flow rate, total protein (BCA), mucin 5B, albumin (western blot), total IgA, lactoferrin and myeloperoxidase levels (ELISA) were determined. RESULTS: Trends of decreasing UWS and SWS flow rates and total IgA levels were observed. At days 7 and 11, increases in lactoferrin and albumin levels were found in UWS and SWS. A positive correlation was found between OMNI scores and albumin and lactoferrin levels in SWS (R2  = .56, p = .029 and R2  = .49, p = .043, respectively). In part B, cryotherapy significantly lowered peak OMNI scores. CONCLUSION: Compositional changes in saliva reflecting inflammation were found in the first days after HSCT, and the use of cryotherapy in the second part was associated with decreased OM severity.

Haptoglobin as a treatment monitoring factor in feline plasmacytic gingivostomatitis.

INTRODUCTION: feline plasmacytic gingivostomatitis is an important and fairly common chronic disease. Its complex aetiology - which involves infectious agents, immunological disorders, and even genetic factors adds to the considerable difficulty of its treatment. MATERIALS AND METHODS: the study was performed on 33 cats, 26 animals diagnosed with plasmacytic gingivostomatitis (study group) and 7 clinically healthy cats (control group). The study extended over four examination periods during which clinical and X-ray examinations, morphological and biochemical blood tests, as well as haptoglobin essays were performed. RESULTS: the biochemical and haematological parameters were within normal limits. Blood serum haptoglobin measured on the first day of the treatment was above physiological levels, however its serum concentration decreased as the treatment progressed. CONCLUSIONS: in the present study, despite the bacterial inflammatory condition of periodontal pockets, after the treatment was concluded and symptoms alleviated, neither clinical examinations nor haptoglobin essays revealed deviations from values commonly accepted as normal. Fluctuations in blood serum haptoglobin levels proved to be a useful prognostic in determining the duration of necessary treatment.

On the pathogenesis of mTOR inhibitor-associated stomatitis (mIAS)-studies using an organotypic model of the oral mucosa.

OBJECTIVE: mTOR inhibitor treatment of solid cancers is associated with mTOR inhibitor-associated stomatitis (mIAS) a common, significant, dose-limiting toxicity, with aphthous-like lesions. Our objective was to assess the utility of a new organotypic model in defining mIAS' pathogenesis. MATERIALS AND METHODS: The effect of everolimus on organotypic human oral mucosa was studied. Sterile specimens were assessed 24 and 48 h after exposure to varying concentrations of everolimus. Morphologic changes and measures of apoptosis, proliferation, and levels of six Th1 and Th2 cytokines were studied. RESULTS: Following a 24-h incubation, concentrations of 500 ng ml-1 of everolimus resulted in histological changes consistent with epithelial injury, disorganization and pre- or early apoptosis, increased TUNEL-positive staining (P < 0.05) and reduced PCNA-positive staining cells (P < 0.001) and increased levels of IL-6 (P < 0.0001), IL-8 (P < 0.01), and IFN-γ (P < 0.09). CONCLUSIONS: Everolimus elicited epithelial damage manifest by morphologic changes, increased apoptosis, and decreased proliferation with concurrent release of keratinocyte-derived pro-inflammatory cytokines in the absence of bacteria. The extent of the effect was concentration and time dependent. These results suggest that mIAS is likely initiated by direct epithelial injury, independent of the microbiome. Keratinocyte cytokine release could likely play a role in accelerating an inflammatory infiltrate.

TNF as marker of oral candidiasis, HSV infection, and mucositis onset during chemotherapy in leukemia patients.

OBJECTIVE: To assess changes in the salivary expression of IL-1α, IL-1ß, IL-2, IL-6, IL-10, IL-17, and TNF in acute leukemia (AL) patients before and during chemotherapy, and its association with HSV infection, oral candidiasis (OC), and oral mucositis (OM) onset. METHODS: Cohort study in AL patients >15 years starting induction chemotherapy at a Mexican oncological center (2013-2014). Onset of oral lesions (OLs) was assessed during follow-up, and saliva was obtained at baseline, at visit 2 (days 4-12), and at visit 3 (days 13-21) after chemotherapy, treated with a protease inhibitor and stored at -70°C. An enzyme-linked immunosorbent assay was performed. Cox proportional hazards regression models were constructed to estimate hazard ratios and its 95% CI (HR, 95% CI) for OL development. RESULTS: Forty-one patients were followed up, and 17 (41.5%) developed OLs. OL patients had higher baseline salivary IL-1α than those without lesions (p = 0.040). During visit 2, OL patients had higher levels of IL-1α (p = 0.033), IL-1ß (p = 0.016), IL-6 (p = 0.035), and TNF (p = 0.019) than those who did not develop OLs. Patients with HSV infection, OC, and OM showed higher salivary TNF levels during follow-up (HR: 3.52, 95% CI: 1.35-9.14, p = 0.010). CONCLUSION: AL patients undergoing chemotherapy with high salivary TNF levels were more likely to develop HSV infection, OC, and OM.

Effect of photobiomodulation therapy on reducing the chemo-induced oral mucositis severity and on salivary levels of CXCL8/interleukin 8, nitrite, and myeloperoxidase in patients undergoing hematopoietic stem cell transplantation: a randomized clinical trial.

Oral mucositis (OM) is the most common debilitating complication among patients undergoing hematopoietic stem cell transplantation (HSCT). Photobiomodulation therapy (PBM) has shown beneficial effects in the treatment of OM, but few studies have evaluated its biological effects. This study evaluated the effect of PBM on the reduction of OM severity in patients undergoing HSCT and its relation to the modulation of the inflammatory response. Fifty-one patients were randomly assigned to two groups: PBM [submitted to PBM from admission (AD) to D+7] (n = 27) and control (n = 24) [received oral hygiene]. OM severity was assessed daily using the WHO scale. Saliva samples were collected on AD, D+7, and hospital discharge (HD) to measure CXCL8/interleukin 8, using cytometric bead array analysis and nitrite (NO) and myeloperoxidase (MPO) using colorimetric methods. PBM significantly reduced the severity of OM from D+7 to D+11 (p < 0.05). All non-interventional patients (controls) who developed grade 2 or higher OM induced an increase of CXCL8 in saliva (n = 14) on D+7. PBM led to a decrease in CXCL8 on D+7 in 85% of patients, while 70.8% of patients in the control group presented an increase in this chemokine (p = 0.007). NO decreased from AD to D+7 in the PBM group (p > 0.05). MPO significantly decreased on D+7 in both groups (p < 0.05). PBM brought about a reduction in the severity of OM in patients undergoing HSCT, and this reduction was associated with a decrease in CXCL8 salivary levels.

Expression of salivary biomarkers in patients with oral mucositis: evaluation by SELDI-TOF/MS.

OBJECTIVE: This study aims to evaluate changes in proteomic salivary profile of patients with oral mucositis after adjuvant cancer treatments. MATERIALS AND METHODS: Samples were collected from patients after adjuvant cancer therapies, and were analyzed by means of SELDI/TOF. Patients were separated in two groups: patients affected by mucositis (MUCOSITIS) and patient without mucositis (NO MUCOSITIS). All patients were divided in function of the anticancer treatment: patients who had radiotherapy (MUCOSITIS RADIO), had not radiotherapy (MUCOSITIS NO RADIO), had chemotherapy (MUCOSITIS CHEMO), and those who had not chemotherapy (MUCOSITIS NO CHEMO). Statistical evaluation PCA (Principal Component Analysis) was conducted with the software BIO-RAD Data Manager(™) (Version 3.5). RESULTS: We found the increased peaks of 3443, 3487, and 4135 m/z in MUCOSITIS group, while 6237 m/z was reduced. These same peaks would the same modifications in MUCOSITIS RADIO, while in MUCOSITIS CHEMIO are increased 3443 and 6237 m/z but 3487, 4135 m/z are reduced. These data were confirmed by the PCA. CONCLUSION: Anticancer therapy influenced the level expression of many salivary biomarkers in mucositis with a good significance. Therefore, 3443, 3487, 4135, and 6237 m/z are good biomarker candidates of oral mucositis.

Hydroalcoholic extract of Carum carvi L. in oral mucositis: a clinical trial in male golden hamsters.

OBJECTIVES: Several studies have attempted to prevent or improve oral mucositis (OM) but have not produced a qualified treatment yet. This study evaluates the effects of Carum carvi L. (caraway) hydroalcoholic extract (CHE) as one of the traditional medicinal plants in 5-fluorouracil (5-FU)-induced OM in golden hamsters. MATERIALS AND METHODS: OM was induced in 54 male golden hamsters by 5-FU and cheek pouch scratching. Starting from day 12, 500 and 1000 mg kg(-1) per day topical CHE were administered. Pouch histopathology score, malondialdehyde and reduced glutathione contents, and activity of myeloperoxidase plus microbial cultures of cheek pouch, antimicrobial properties of CHE, and essential oil constituents were evaluated. RESULTS: Lower histopathology score (0, 1, and 2) and malondialdehyde level, higher reduced glutathione level and activities of myeloperoxidase were detected in 1000 and 500 mg kg(-1) per day topical CHE and control groups, respectively (P < 0.001). The CHE was more potent against Staphylococcus epidermidis and Streptococcus intermedius. γ-Terpinene (37.2%) was identified as the main constituent of essential oil. CONCLUSION: The use of CHE in topical form may be associated with reduced intensity of OM. This may be due to appropriate antibacterial activity and terpinene contents.

Proliferation, migration, and expression of oral-mucosal-healing-related genes by oral fibroblasts receiving low-level laser therapy after inflammatory cytokines challenge.

BACKGROUND AND OBJECTIVES: Increased expression of inflammatory cytokines in the oral cavity has been related to the etiopathogenesis of oral mucositis and to delayed oral mucosal repair. Low-level laser therapy (LLLT) stimulates proliferation and migration of gingival fibroblasts, but the effects of specific inflammatory cytokines on oral mucosal cells and the modulation of these effects by LLLT have not been fully investigated. Therefore, this study investigated the effects of LLLT on oral fibroblasts after being challenged by oral-mucositis-related inflammatory cytokines. METHODS: Human gingival fibroblasts were seeded in plain culture medium (DMEM) containing 10% fetal bovine serum (FBS) for 24 hours. Then, cells were kept in contact with inflammatory cytokines (TNF-α, IL-1ß, IL-6, and IL-8) in serum-free DMEM for 24 hours. After this period, cells were subjected to LLLT with a diode laser device (LaserTABLE, InGaAsP, 780 nm, 25 mW) delivering energy doses from 0.5 to 3 J/cm2 . Irradiation was repeated for 3 consecutive days. Twenty-four hours after the last irradiation, cell migration (wound-healing and transwell migration assays), cell proliferation (BrdU), gene expression of COL-I and growth factors (real-time PCR), and synthesis of COL-I (Sirius Red assay) and VEGF (ELISA) were assessed. Data were subjected to two-way ANOVA and Tukey's tests or Kruskall-Walis and Mann-Whitney tests (P < 0.05). RESULTS: The inflammatory cytokines decreased the migration capacity of gingival fibroblasts. However, a statistically significant difference was observed only for IL-6, detected by transwell assay, where 30% less cells migrated through the pores (P < 0.05) and IL-8, with an increased wound area (116%; P < 0.05), detected by the wound healing method. Cell proliferation was not affected by contact with cytokines, while growth factors and COL-I expression (approximately 80%; P < 0.05), as well as VEGF synthesis (approximately 20%; P < 0.05), were decreased after contact to all tested cytokines. The opposite was seen for total collagen synthesis. LLLT promoted an acceleration of fibroblast migration (30%; P < 0.05) and proliferation (112%; P < 0.05) when delivering 0.5 J/cm2 to the cells previously in contact with the inflammatory cytokines. Gene expression of VEGF (approximately 30%; P < 0.05), and EGF (17%; P < 0.05), was stimulated by LLLT after contact with TNF-α and IL-6. CONCLUSION: LLLT can counteract the negative effects of high concentrations of inflammatory cytokines, especially IL-6 and IL-8 on gingival fibroblast functions directly related to the wound-healing process. Lasers Surg. Med. 48:1006-1014, 2016. © 2016 Wiley Periodicals, Inc.

Inhibition of caspases protects mice from radiation-induced oral mucositis and abolishes the cleavage of RNA-binding protein HuR.

The oral mucosal epithelium is typically insulted during chemotherapy and ionizing radiation (IR) therapy and disposed to mucositis, which creates painful inflammation and ulceration in the oral cavity. Oral mucositis alters gene expression patterns, inhibits cellular growth, and initiates cell death in the oral epithelial compartments. Such alterations are governed by several different factors, including transcription factors, RNA-binding proteins, and microRNAs. IR-induced post-transcriptional regulation of RNA-binding proteins exists but is poorly studied in clinically relevant settings. We herein report that the RNA-binding protein human antigen R (HuR) undergoes cleavage modification by caspase-3 following IR-induced oral mucositis and subsequently promotes the expression of the pro-apoptotic factor BAX (Bcl-2-associated X protein), as well as cell death. Further analyses revealed that the HuR cleavage product-1 (HuR-CP1) directly associates and stabilizes the BAX mRNA and concurrently activates the apoptotic pathway. On the other hand, a noncleavable isoform of HuR promotes the clonogenic capacity of primary oral keratinocytes and decreases the effect of IR-induced cell death. Additionally, specific inhibition of caspase-3 by a compound, NSC321205, increases the clonogenic capacity of primary oral keratinocytes and causes increased basal layer cellularity, thickened mucosa, and elevated epithelial cell growth in the tongues of mice with oral mucositis. This protective effect of NSC321205 is mediated by a decrease in caspase-3 activity and the consequent inhibition of HuR cleavage, which reduces the expression of BAX in mice with IR-induced oral mucositis. Thus, we have identified a new molecular mechanism of HuR in the regulation of mRNA turnover and apoptosis in oral mucositis, and our data suggest that blocking the cleavage of HuR enhances cellular growth in the oral epithelial compartment.

Melatonin blunts the mitochondrial/NLRP3 connection and protects against radiation-induced oral mucositis.

Mucositis is a common and distressing side effect of chemotherapy or radiotherapy that has potentially severe consequences, and no treatment is available. The purpose of this study was to analyze the molecular pathways involved in the development of oral mucositis and to evaluate whether melatonin can prevent this pathology. The tongue of male Wistar rats was subjected to irradiation (X-ray YXLON Y.Tu 320-D03 irradiator; the animals received a dose of 7.5 Gy/day for 5 days). Rats were treated with 45 mg/day melatonin or vehicle for 21 days postirradiation, either by local application into their mouths (melatonin gel) or by subcutaneous injection. A connection between reactive oxygen species, generating mitochondria and the NLRP3 (NLR-related protein 3 nucleotide-binding domain leucine-rich repeat containing receptor-related protein 3) inflammasome, has been reported in mucositis. Here, we show that mitochondrial oxidative stress, bioenergetic impairment and subsequent NLRP3 inflammasome activation are involved in the development of oral mucositis after irradiation and that melatonin synthesized in the rat tongue is depleted after irradiation. The application of melatonin gel restores physiological melatonin levels in the tongue and prevents mucosal disruption and ulcer formation. Melatonin gel protects the mitochondria from radiation damage and blunts the NF-κB/NLRP3 inflammasome signaling activation in the tongue. Our results suggest new molecular pathways involved in radiotherapy-induced mucositis that are inhibited by topical melatonin application, suggesting a potential preventive therapy for mucositis in patients with cancer.

Evaluation of edaravone against radiation-induced oral mucositis in mice.

Oral mucositis induced by radiotherapy for cancers of the head and neck reduce the quality of life of patients. However, effective therapeutic agents are lacking. Symptomatic treatment involves local anesthesia and analgesia. We focused on the antioxidant effects of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one; Radicut(®)). Oral mucositis was induced on the tongue tips of mice using a single dose of X-rays (20 Gy). To evaluate the protective effect of edaravone (30 and 300 mg/kg), administration was carried out 30 min before irradiation. Survival, oral mucositis score, myeloperoxidase activity, and levels of 2-Thiobarbituric acid reactive substances were measured, and all were improved compared with those of control mice. A significant difference was not found in terms of survival due to edaravone. Histopathologic findings also highlighted the beneficial features of edaravone. Edaravone reduced the production of reactive oxygen species. These findings suggest that the protective effect of edaravone against radiation-induced oral mucositis is through an antioxidant effect.