Periodontal disease-associated compensatory expression of osteoprotegerin is lost in type 1 diabetes mellitus and correlates with alveolar bone destruction by regulating osteoclastogenesis

Alveolar bone resorption results from the inflammatory response to periodontal pathogens. Systemic diseases that affect the host response, such as type 1 diabetes mellitus (DM1), can potentiate the severity of periodontal disease (PD) and accelerate bone resorption. However, the biological mechanisms by which DM1 modulates PD are not fully understood. The aim of this study was to determine the influence of DM1 on alveolar bone resorption and to evaluate the role of receptor activator of nuclear factor-kappaB ligand (RANKL)/osteoprotegerin (OPG) in osteoclastogenesis in rats. PD was induced by means of ligature in nondiabetic and in streptozotocyn-induced DM1 rats. Morphological and morphometric analyses, stereology and osteoclast counting were performed. RANKL and OPG mRNA levels, protein content, and location were determined. PD caused alveolar bone resorption, increased the number of osteoclasts in the alveolar bone crest and also promoted changes in RANKL/OPG mRNA expression. DM1 alone showed alveolar bone destruction and an increased number of osteoclasts at the periapical and furcal regions. DM1 exacerbated these characteristics, with a greater impact on bone structure, resulting in a low OPG content and a higher RANKL/OPG ratio, which correlated with prominent osteoclastogenesis. This work demonstrates that the effects of PD and DM1 enhance bone destruction, confirms the importance of the RANKL signaling pathway in bone destruction in DM1 in animal models and suggests the existence of alternative mechanisms potentiating bone degradation in PD.

Relevance of the Myeloid Differentiation Factor 88 (MyD88) on RANKL, OPG, and Nod Expressions Induced by TLR and IL-1R Signaling in Bone Marrow Stromal Cells

The myeloid differentiation factor 88 (MyD88) plays a pivotal role in Toll-like receptor (TLR)- and interleukin-1 receptor (IL-1R)-induced osteoclastogenesis. We examined the role of MyD88 on p38 mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) activation and nucleotide-binding oligomerization domain (Nod) induction by lipopolysaccharide (LPS) and IL-1 beta, and their effect on receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) production in bone marrow stromal cell (BMSC). RANKL, Nod1, Nod2, NF-κB, and p38 protein levels were determined by Western blot. Nod2 was stimulated with muramyl dipeptide (MDP) prior to TLR4 stimulation with LPS. MyD88 deficiency markedly inhibited RANKL expression after LPS stimulation and increased OPG messenger RNA (mRNA) production. Also, MyD88 was necessary for NF-κB and p38 MAPK activation. MDP alone did not induce RANKL and OPG expressions; however, when combined with LPS, their expressions were significantly increased (p < 0.05). Our results support that MyD88 signaling has a pivotal role in osteoclastogenesis thought NF-κB and p38 activation. Nod2 and especially Nod1 levels were influenced by MyD88.

Interação de fibroblastos associados ao câncer em co-cultura com linguagens tumorias mamárias e a resposta terapêutica em o uso da melatonina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The involvement of TLR2 and TLR4 in cytokine and nitric oxide production in visceral leishmaniasis patients before and after treatment with anti-leishmanial drugs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Interleukin-18 increases TLR4 and mannose receptor expression and modulates cytokine production in human monocytes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevance of the Myeloid Differentiation Factor 88 (MyD88) on RANKL, OPG, and Nod Expressions Induced by TLR and IL-1R Signaling in Bone Marrow Stromal Cells

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Melatonin attenuates the TLR4-mediated inflammatory response through MyD88-and TRIF-dependent signaling pathways in an in vivo model of ovarian cancer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nitric oxide and brazilian propolis combined accelerates tissue repair by modulating cell migration, cytokine production and collagen deposition in experimental leishmaniasis

The fact that drugs currently used in the treatment of Leishmania are highly toxic and associated with acquired resistance has promoted the search for new therapies for treating American tegumentary leishmaniasis (ATL). In this study, BALB/c mice were injected in the hind paw with Leishmania (Leishmania) amazonensis and subsequently treated with a combination of nitric oxide (NO) donor (cis-[Ru(bpy)(2)imN(NO)](PF6)(3)) (Ru-NO), given by intraperitoneal injection, and oral Brazilian propolis for 30 days. Ru-NO reached the center of the lesion and increased the NO level in the injured hind paw without lesion exacerbation. Histological and immunological parameters of chronic inflammation showed that this combined treatment increased the efficacy of macrophages, determined by the decrease in the number of parasitized cells, leading to reduced expression of proinflammatory and tissue damage markers. In addition, these drugs in combination fostered wound healing, enhanced the number of fibroblasts, pro-healing cytokines and induced collagen synthesis at the lesion site. Overall, our findings suggest that the combination of the NO donor Ru-NO and Brazilian propolis alleviates experimental ATL lesions, highlighting a new therapeutic option that can be considered for further in vivo investigations as a candidate for the treatment of cutaneous leishmaniasis.

Improvement of the physical performance is associated with activation of NO/PGC-l alpha/mtTFA signaling pathway and increased protein expressions of electron transport chain in gastrocnemius muscle from rats supplemented with L-arginine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Humoral immune responses against the malaria vaccine candidate antigen Plasmodium vivax AMA-1 and IL-4 gene polymorphisms in individuals living in an endemic area of the Brazilian Amazon

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Association of a Large Panel of Cytokine Gene Polymorphisms with Complications and Comorbidities in Type 2 Diabetes Patients

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Clinical Influence of Different Intracanal Medications on Th1-type and Th2-type Cytokine Responses in Apical Periodontitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Stem cell factor: a hemopoietic cytokine with important targets in asthma

We review evidence that Stem Cell Factor (SCF) plays an important role in the pathophysiology of asthma. SCF is produced by a wide variety of cells present in asthmatic lung, including mast cells and eosinophils. Its receptor, c-kit, is broadly expressed on mature mast cells and eosinophils. SCF promotes recruitment of mast cell progenitors into tissues, as well as their local maturation and activation. It also promotes eosinophil survival, maturation and functional activation. SCF enhances IgE-dependent release of mediators from mast cells, including histamine, leukotrienes, cytokines (TNF-alpha, IL-5, GM-CSF) and chemokines (RANTES/CCL5, MCP-1/CCL2, TARC/CCL17 e MDC/CCL22); it is required for IL-4 production in mast cells. SCF, acting in concert with IgE, also upregulates the expression and function of CC chemokine receptors in mast cells. Structural and resident airway cells express increased levels of SCF in the bronchus of asthmatic patients. In a murine model of asthma, allergen exposure increased production of SCF by epithelial cells and alveolar macrophages, which was transient and paralleled by histamine release. SCF induced long-lived airway hyperreactivity, which was prevented by local neutralization of SCF, as well as by inhibitors of the production or activity of cysteinyl-leukotrienes. Together, these observations suggest that SCF has an important role in asthma.

Inhibition of diethylnitrosamine-initiated alcohol-promoted hepatic inflammation and precancerous lesions by flavonoid luteolin is associated with increased sirtuin 1 activity in mice

Chronic and excessive alcohol consumption is an established risk for hepatic inflammation and carcinogenesis. Luteolin is one of the most common flavonoids present in plants and has potential beneficial effects against cancer. In this study, we examined the effect and potential mechanisms of luteolin supplementation in a carcinogen initiated alcohol-promoted pre-neoplastic liver lesion mouse model. C57BL/6 mice were injected with diethylnitrosamine (DEN) [i.p. 25 mg/kg of body weight (BW)] at 14 days of age. At 8 weeks of age mice were group pair-fed with Lieber-DeCarli liquid control diet or alcoholic diet [ethanol (EtOH) diet, 27% total energy from ethanol] and supplemented with a dose of 30 mg luteolin/kg BW per day for 21 days. DEN-injected mice fed EtOH diet displayed a significant induction of pre-neoplastic lesions, a marker associated with presence of steatosis and inflammation. Dietary luteolin significantly reduced the severity and incidence of hepatic inflammatory foci and steatosis in DEN-injected mice fed EtOH diet, as well the presence of preneoplastic lesions. There was no difference on hepatic protein levels of sirtuin 1 (SIRT1) among all groups; however, luteolin supplementation significantly reversed alcohol-reduced SIRT1 activity assessed by the ratio of acetylated and total forkhead box protein O1 (FoXO1) and SIRT1 target proliferator-activated receptor gamma, coactivator 1 alpha (PGC1α). Dietary intake of luteolin prevents alcohol promoted pre-neoplastic lesions, potentially mediated by SIRT1 signaling pathway.

Influence of sex on basal and dickkopf-1 regulated gene expression in the bovine morula

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)