RESUMO
In response to brain injury or infections, astrocytes become reactive, undergo striking morphological and functional changes, and secrete and respond to a spectrum of inflammatory mediators. We asked whether reactive astrocytes also display adaptive responses during sterile IL-1ß-induced neuroinflammation, which may limit tissue injury associated with many disorders of the central nervous system. We found that astrocytes display days-to-weeks long specific tolerance of cytokine genes, which is coordinated by NF-κB family member, RelB. However, in contrast to innate immune cells, astrocytic tolerance does not involve epigenetic silencing of the cytokine genes. Establishment of tolerance depends on persistent higher levels of RelB in tolerant astrocytes and its phosphorylation on serine 472. Mechanistically, this phosphorylation prevents efficient removal of RelB from cytokine promoters by IκBα and helps to establish tolerance. Importantly, ablation of RelB from astrocytes in mice abolishes tolerance during experimental neuroinflammation in vivo.
Assuntos
Imunidade Adaptativa/fisiologia , Astrócitos/imunologia , Inflamação/metabolismo , Fator de Transcrição RelB/metabolismo , Animais , Encéfalo/imunologia , Citocinas/metabolismo , Epigênese Genética , Células HEK293 , Humanos , Tolerância Imunológica/fisiologia , Camundongos Transgênicos , Neuroimunomodulação , Fosforilação , Sirtuína 1/metabolismo , Fator de Transcrição RelB/genéticaRESUMO
BACKGROUND: A 6-week Phase I clinical trial was performed to primarily evaluate the safety and secondarily determine the preliminary efficacy of a novel biological solution, ST266, comprised of a mixture of cytokines, growth factors, nucleic acids, and lipids secreted by cultured amnion-derived multipotent progenitor cells on gingival inflammation. METHODS: Fifty-four adults with gingivitis/periodontitis were randomly assigned to 1X ST266 or diluted 0.3X ST266 or saline topically applied on facial/lingual gingiva (20 µL/tooth). Safety was assessed through oral soft/hard tissue exam, adverse events, and routine laboratory tests. Efficacy was assessed by modified gingival index (MGI), bleeding on probing, plaque index, probing depth (PD), and clinical attachment level (CAL). Assessments were performed on day 0, 8, 12, and 42. ST266 and saline applied daily starting at day 0 through day 12 except weekend days. Plasma was analyzed for safety and proinflammatory cytokines, interleukin (IL)-1ß, IL-6, tumor necrosis factor-alpha, and interferon gamma. Gingival crevicular fluid (GCF) was analyzed for the same cytokines. Subgingival plaque was primarily analyzed by checkerboard DNA-DNA hybridization. Comparisons with saline were modeled through a generalized estimating equations method adjusting for baseline. RESULTS: No safety concern was found related to ST266. Statistically significant reduction in MGI was noted at day 42 by 1X ST266 compared with saline (P = 0.044). PD and CAL were reduced by both doses of ST266 at day 42 (P <0.01) and by 1X ST266 at day 12 (P <0.05). GCF IL-1ß and IL-6 levels were reduced by both doses of ST266 at day 12 (P <0.05, P <0.01, respectively). IL-6 was also significantly reduced in plasma of both ST266 groups (P <0.05). Significant reductions in red complex bacteria were detected in both ST266 doses. CONCLUSIONS: In this "first in human oral cavity" study, topical ST266 was safe and effective in reducing gingival inflammation in 6 weeks. Longitudinal studies with large sample sizes are warranted to assess the therapeutic value of this novel host modulatory compound in the treatment of periodontal diseases.
Assuntos
Âmnio , Gengivite , Adulto , Citocinas/análise , Índice de Placa Dentária , Líquido do Sulco Gengival/química , Gengivite/tratamento farmacológico , HumanosRESUMO
Background: Periodontal disease is among the sixth most common inflammatory diseases worldwide with high risk to promote complications from other inflammatory diseases including diabetes, cardiovascular disease and Alzheimer's Disease. Failure of active resolution of inflammation pathways is implicated in pathogenesis of periodontal diseases, including gingivitis. Lipoxin A4 (LXA4), a member of the specialized pro-resolving lipid mediators (SPMs) that drive resolution of inflammation via GPC-receptor mediated pathways, offered therapeutic advantages in preclinical models of periodontitis. Methods: We conducted a randomized, placebo-controlled, parallel-group Phase 1 clinical trial to determine the safety and preliminary efficacy of an LXA4 analog in patients with gingival inflammation. One hundred twenty-seven (127) individuals were randomized to daily use of an oral rinse containing a LXA4 mimetic, methyl ester-benzo-lipoxin A4 (BLXA4), placebo rinse or a no-rinse control group for 28 days. Treatment emergent adverse events (TEAEs) were assessed for safety, the primary outcome. Secondary outcomes included the change in the level of gingival inflammation and periodontal pocket depth (PD). Serum SPMs were monitored using targeted lipid mediator lipidomics to assess potential systemic impact of BLXA4. Results: The frequency of TEAEs was similar in BLXA4 and placebo-treated groups with no study-related SAEs. Once-daily rinsing with BLXA4 for 28-days resulted in a greater decrease in gingival inflammation compared to placebo rinse and no-rinse control groups (mean change: 0.26 GI unit vs 0.21 and 0.17, respectively). PD reduction was also greater with BLXA4 oral rinse compared to placebo and no-rinse groups (mean reduction: 1.23 mm vs. 0.71 mm and 0.46 mm, respectively). Topical application of BLXA4 increased serum levels of SPMs. Conclusion: Treatment with BLXA4 reduces local inflammation, and increases abundance of pro-resolution molecules systemically, which may dampen inflammation that can mediate progression and course of inflammatory diseases beyond periodontitis. Clinical Trial Registration: ClinicalTrials.gov, identifier (NCT02342691).
Assuntos
Gengivite/tratamento farmacológico , Lipoxinas/administração & dosagem , Periodontite/tratamento farmacológico , Administração Tópica , Adolescente , Adulto , Idoso , Feminino , Humanos , Lipoxinas/efeitos adversos , Masculino , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: The authors conducted two double-blinded, randomized, multicenter clinical trials to determine the efficacy and clinical anesthetic characteristics of 4 percent articaine hydrochloride (HCl) with 1:200,000 epinephrine (A200) as compared with those of 4 percent articaine HCl with 1:100,000 epinephrine (A100) and 4 percent articaine HCl without epinephrine (Aw/o). METHODS: During separate testing sessions, members of the authors' research team used three articaine study formulations to induce either inferior alveolar nerve block anesthesia (Trial 1) or maxillary infiltration anesthesia (Trial 2). In each trial, subjects received, in a randomized sequence, each of the three formulations to determine efficacy (success rate) and anesthetic characteristics (onset time and duration). The authors evaluated pulpal anesthesia via subjects' response to electric pulp testing (EPT). RESULTS: A total of 126 subjects were enrolled in the two studies (63 subjects in each trial). In both mandibular and maxillary trials, the success rates for inducing profound anesthesia (EPT score > 80), the mean onset times and the mean durations of anesthesia were similar for both epinephrine-containing formulations (A200 and A100). In subjects who received the formulation containing no epinephrine (Aw/o), the success rate for profound anesthesia was significantly less. CONCLUSION: These studies demonstrated that the inclusion of epinephrine in 4 percent articaine anesthetic formulations is essential for achieving profound anesthesia. The authors found that the A200 formulation provided a level of pulpal anesthesia comparable with that of the A100 formulation.