Tumor necrosis factor α, and agonist and antagonists of cannabinoid receptor type 1 and type 2 alter the immunophenotype of stem cells from human exfoliated deciduous teeth.

OBJECTIVE: To verify the involvement of the endocannabinoid system in the immunomodulatory profile of stem cells from human exfoliated deciduous teeth, in the presence or absence of TNF-α, and agonist and antagonists of CB1 and CB2. METHODS: Stem cells from human exfoliated deciduous teeth were cultured in the presence or absence of an agonist, anandamide, and two antagonists, AM251 and SR144528, of CB1 and CB2 receptors, with or without TNF-α stimulation. For analysis of immunomodulation, surface molecules linked to immunomodulation, namely human leukocyte antigen-DR isotype (HLA-DR), and programmed death ligands 1 (PD-L1) and 2 (PD-L2) were measured using flow cytometry. RESULTS: The inhibition of endocannabinoid receptors together with the proinflammatory effect of TNF-α resulted in increased HLA-DR expression in stem cells from human exfoliated deciduous teeth, as well as, in these cells acquiring an anti-inflammatory profile by enhancing the expression of PD-L1 and PD-L2. CONCLUSION: Stem cells from human exfoliated deciduous teeth respond to the endocannabinoid system and TNF-α by altering key immune response molecules. Inhibition of endocannabinoid receptors and TNF-α led to an increase in HLA-DR, PD-L1, and PD-L2 levels in stem cells from human exfoliated deciduous teeth. This study shows the interaction between mesenchymal stromal cells and the immune and endocannabinoid systems.

Tumor necrosis factor α, and agonist and antagonists of cannabinoid receptor type 1 and type 2 alter the immunophenotype of stem cells from human exfoliated deciduous teeth

ABSTRACT Objective To verify the involvement of the endocannabinoid system in the immunomodulatory profile of stem cells from human exfoliated deciduous teeth, in the presence or absence of TNF-α, and agonist and antagonists of CB1 and CB2. Methods Stem cells from human exfoliated deciduous teeth were cultured in the presence or absence of an agonist, anandamide, and two antagonists, AM251 and SR144528, of CB1 and CB2 receptors, with or without TNF-α stimulation. For analysis of immunomodulation, surface molecules linked to immunomodulation, namely human leukocyte antigen-DR isotype (HLA-DR), and programmed death ligands 1 (PD-L1) and 2 (PD-L2) were measured using flow cytometry. Results The inhibition of endocannabinoid receptors together with the proinflammatory effect of TNF-α resulted in increased HLA-DR expression in stem cells from human exfoliated deciduous teeth, as well as, in these cells acquiring an anti-inflammatory profile by enhancing the expression of PD-L1 and PD-L2. Conclusion Stem cells from human exfoliated deciduous teeth respond to the endocannabinoid system and TNF-α by altering key immune response molecules.

Evaluation of Resin-Based Material Containing Copaiba Oleoresin (Copaifera Reticulata Ducke): Biological Effects on the Human Dental Pulp Stem Cells.

The purpose of this study was to analyze in vitro the biological effects on human dental pulp stem cells triggered in response to substances leached or dissolved from two experimental cements for dental pulp capping. The experimental materials, based on extracts from Copaifera reticulata Ducke (COP), were compared to calcium hydroxide [Ca(OH)2] and mineral trioxide aggregate (MTA), materials commonly used for direct dental pulp capping in restorative dentistry. For this, human dental pulp stem cells were exposed to COP associated or not with Ca(OH)2 or MTA. Cell cytocompatibility, migration, and differentiation (mineralized nodule formation (Alizarin red assay) and gene expression (RT-qPCR) of OCN, DSPP, and HSP-27 (genes regulated in biomineralization events)) were evaluated. The results showed that the association of COP reduced the cytotoxicity of Ca(OH)2. Upregulations of the OCN, DSPP, and HSP-27 genes were observed in response to the association of COP to MTA, and the DSPP and HSP-27 genes were upregulated in the Ca(OH)2 + COP group. In up to 24 h, cell migration was significantly enhanced in the MTA + COP and Ca(OH)2 + COP groups. In conclusion, the combination of COP with the currently used materials for dental pulp capping [Ca(OH)2 and MTA] improved the cell activities related to pulp repair (i.e., cytocompatibility, differentiation, mineralization, and migration) including a protective effect against the cytotoxicity of Ca(OH)2.

Does Helium Pneumoperitoneum Reduce the Hyperinflammatory Response in Septic Animals during Laparoscopy?

Background/Aim. An exacerbated reaction to peritoneal infection and attendant surgical procedures is characterized by an intense hyperinflammatory state, the magnitude of which is proportional to the severity of tissue injury. Laparoscopy generates lower levels of tissue damage compared with open surgery and should induce less pronounced immune responses. The aim of this study was to determine whether laparoscopy assisted by helium rather than carbon dioxide pneumoperitoneum would induce an attenuated inflammatory state in septic animals. Materials and Methods. Thirty-two Wistar rats were divided randomly into four equal groups, two of which were submitted to carbon dioxide or helium pneumoperitoneum-assisted laparoscopic cecal ligation and puncture (CLP) induced sepsis and subsequent abdominal lavage. Two control groups were submitted to identical laparoscopic procedures with carbon dioxide or helium as insufflator gas but without CLP. After 24 hours, serum levels of tumor necrosis factor alpha (TNF-α), interleukins 1 and 6 (IL-1 and IL-6, respectively), and cortisol were determined. RESULTS: Mean concentrations of I L-1 and IL-6 in the groups of septic animals submitted to laparoscopy with carbon dioxide or helium pneumoperitoneum were not significantly different but were significantly higher than those of their respective non-CLP controls. In contrast, the levels of TNF-α), interleukins 1 and 6 (IL-1 and IL-6, respectively), and cortisol were determined. CONCLUSIONS: Laparoscopy with helium insufflation was similar to carbon dioxide in relation to the inflammatory response since levels of the proinflammatory TNF-α, IL-1, and IL-6 and of the anti-inflammatory cortisol were comparable for both gases.α), interleukins 1 and 6 (IL-1 and IL-6, respectively), and cortisol were determined.

Intestinal microbiota as modulators of the immune system and neuroimmune system: impact on the host health and homeostasis.

Many immune-based intestinal disorders, such as ulcerative colitis and Crohn's disease, as well as other illnesses, may have the intestines as an initial cause or aggravator in the development of diseases, even apparently not correlating directly to the intestine. Diabetes, obesity, multiple sclerosis, depression, and anxiety are examples of other illnesses discussed in the literature. In parallel, importance of the gut microbiota in intestinal homeostasis and immunologic conflict between tolerance towards commensal microorganisms and combat of pathogens is well known. Recent researches show that the immune system, when altered by the gut microbiota, influences the state in which these diseases are presented in the patient directly and indirectly. At the present moment, a considerable number of investigations about this subject have been performed and published. However, due to difficulties on correlating information, several speculations and hypotheses are generated. Thus, the present review aims at bringing together how these interactions work-gut microbiota, immune system, and their influence in the neuroimmune system.

Satellite cells: regenerative mechanisms and applicability in muscular dystrophy.

The satellite cells are long regarded as heterogeneous cell population, which is intimately linked to the processes of muscular recovery. The heterogeneous cell population may be classified by specific markers. In spite of the significant amount of variation amongst the satellite cell populations, it seems that their activity is tightly bound to the paired box 7 transcription factor expression, which is, therefore, used as a canonical marker for these cells. Muscular dystrophic diseases, such as Duchenne muscular dystrophy, elicit severe tissue injuries leading those patients to display a very specific pattern of muscular recovery abnormalities. There have been works on the application of precursors cells as a therapeutic alternative for Duchenne muscular dystrophy and initial attempts have proven the cells inefficient; however later endeavours have proposed solutions for the experiments improving significantly the results. The presence of a range of satellite cells populations indicates the existence of specific cells with enhanced capability of muscular recovery in afflicted muscles.

Advances in cellular technology in the hematology field: What have we learned so far?

Despite the advances in the hematology field, blood transfusion-related iatrogenesis is still a major issue to be considered during such procedures due to blood antigenic incompatibility. This places pluripotent stem cells as a possible ally in the production of more suitable blood products. The present review article aims to provide a comprehensive summary of the state-of-the-art concerning the differentiation of both embryonic stem cells and induced pluripotent stem cells to hematopoietic cell lines. Here, we review the most recently published protocols to achieve the production of blood cells for future application in hemotherapy, cancer therapy and basic research.

Mesenchymal stem cells derived from human exfoliated deciduous teeth (SHEDs) induce immune modulatory profile in monocyte-derived dendritic cells.

BACKGROUND: Mesenchymal stem cells have prominent immune modulatory properties, which may have clinical applications; however their major source, bone marrow, is of limited availability. On the other hand, mesenchymal stem cells derived from human exfoliated deciduous teeth (SHEDs) are readily accessible, but their immune regulatory properties have not been completely investigated. This study was designed, therefore, to evaluate the SHEDs influence on DCs differentiation, maturation, ability to activate T cells and to expand CD4(+)Foxp3(+) T cells. METHODOLOGY/PRINCIPAL FINDINGS: The experiments were based in cellular co-culture during differentiation and maturation of monocyte derived-DCs (moDCs), with, or not, presence of SHEDs. After co-culture with SHEDs, (moDCs) presented lower expression of BDCA-1 and CD11c, in comparison to DC cultivated without SHEDs. CD40, CD80, CD83 and CD86 levels were also decreased in mature DCs (mDCs) after co-cultivation with SHEDs. To assess the ability of SHEDs-exposed moDCs to modulate T cell responses, the former were separated from SHEDs, and co-cultured with peripheral blood lymphocytes. After 5 days, the proliferation of CD4(+) and CD8(+) T cells was evaluated and found to be lower than that induced by moDCs cultivated without SHEDs. In addition, an increase in the proportion of CD4(+)Foxp3(+)IL-10(+) T cells was observed among cells stimulated by mature moDCs that were previously cultivated with SHEDs. Soluble factors released during co-cultures also showed a reduction in the pro-inflammatory cytokines (IL-2, TNF-α and IFN-γ), and an increase in the anti-inflammatory molecule IL-10. CONCLUSION/SIGNIFICANCE: This study shows that SHEDs induce an immune regulatory phenotype in moDCs cells, evidenced by changes in maturation and differentiation rates, inhibition of lymphocyte stimulation and ability to expand CD4(+)Foxp3(+) T cells. Further characterization and validation of this phenomenon could support the use of SHEDs, directly or indirectly for immune modulation in the clinical practice.

Immunoregulatory effects of bone marrow-derived mesenchymal stem cells in the nasal polyp microenvironment.

Nasal polyposis is a severe, chronic inflammatory condition of the paranasal sinuses and is frequently associated with asthma and aspirin sensitivity. Mesenchymal stem cells exhibit a potent immunosuppressive effect in several inflammatory conditions, and their role in nasal polyposis remains little explored. Hence, we investigated whether bone marrow-derived mesenchymal stem cells could modulate cell phenotype in the nasal polyp milieu. After coculture with mesenchymal stem cells, the frequency of these inflammatory cells was found to decrease. Furthermore, mesenchymal stem cells promoted strong inhibition of CD4+ and CD8+ T cell proliferation, increased the frequency of CD4+CD25+Foxp3 T cells, and changed the global cytokine profile from an inflammatory to an anti-inflammatory response. We believe that mesenchymal stem cells may be a very useful adjunct for investigation of the inflammatory process in nasal polyposis, contributing to better understanding of the inflammatory course of this condition.

Dental pulp stem cells express proteins involved in the local invasiveness of odontogenic myxoma.

Little is known about the histogenesis of the odontogenic myxoma (OM). Dental pulp stem cells could be candidate precursors of OM because both OM and the dental pulp share the same embryological origin: the dental papilla. For the purpose of comparing OM and stem cells, this study analyzed the expression of two proteins related to OM invasiveness (MMP-2 and hyaluronic acid) in human immature dental pulp stem cells (hIDPSCs). Three lineages of hIDPSCs from deciduous and permanent teeth were used in this study. Immunofluorescence revealed positive reactions for MMP-2 and hyaluronic acid (HA) in all hIDPSCs. MMP-2 appeared as dots throughout the cytoplasm, whereas HA appeared either as diffuse and irregular dots or as short fibrils throughout the cytoplasm and outside the cell bodies. The gene expression profile of each cell lineage was evaluated using RT-PCR analysis, and HA was expressed more intensively than MMP-2. HA expression was similar among the three hIDPSCs lineages, whereas MMP-2 expression was higher in DL-1 than in the other cell lines. The expression of proteins related to OM invasiveness in hIDPSCs could indicate that OM originates from dental pulp stem cells.

Dental pulp stem cells express proteins involved in the local invasiveness of odontogenic myxoma

Little is known about the histogenesis of the odontogenic myxoma (OM). Dental pulp stem cells could be candidate precursors of OM because both OM and the dental pulp share the same embryological origin: the dental papilla. For the purpose of comparing OM and stem cells, this study analyzed the expression of two proteins related to OM invasiveness (MMP-2 and hyaluronic acid) in human immature dental pulp stem cells (hIDPSCs). Three lineages of hIDPSCs from deciduous and permanent teeth were used in this study. Immunofluorescence revealed positive reactions for MMP-2 and hyaluronic acid (HA) in all hIDPSCs. MMP-2 appeared as dots throughout the cytoplasm, whereas HA appeared either as diffuse and irregular dots or as short fibrils throughout the cytoplasm and outside the cell bodies. The gene expression profile of each cell lineage was evaluated using RT-PCR analysis, and HA was expressed more intensively than MMP-2. HA expression was similar among the three hIDPSCs lineages, whereas MMP-2 expression was higher in DL-1 than in the other cell lines. The expression of proteins related to OM invasiveness in hIDPSCs could indicate that OM originates from dental pulp stem cells.

Biological versatility of crotamine--a cationic peptide from the venom of a South American rattlesnake.

IMPORTANCE OF THE FIELD: Molecules isolated from animals, insects, plants or microorganisms can provide prototypes for design of biopharmaceutical products. Some venom toxins and their derivatives are used in medicine, while others provide templates for development of new drugs. AREAS COVERED IN THIS REVIEW: The mild toxin, crotamine, a small basic low-molecular-weight polypeptide purified from the venom of a South American rattlesnake, Crotalus durissus terrificus. Crotamine was discovered more than 50 years ago and only in the past six years has its exceptional biological versatility been demonstrated. Particularly, its cell-penetrating ability, which allows crotamine to cross cell membranes and to accumulate in the nucleus; its use for intracellular vesicle tracking and as a cell cycle marker and its capability for delivering DNA into replicating mammalian cells. Both antimicrobial action and potential selective antitumor activity of crotamine have also been found. WHAT THE READER WILL GAIN: Multidisciplinary approaches and pathways of discovery placed crotamine in a rare category of versatile biomolecules, in which concentration, molecular target preference, structural ancestry and specificity toward biological membranes play an integral role. TAKE HOME MESSAGE: Crotamine is a druggable peptide with high potential for use as an imaging agent for detecting dividing cells, for intracellular delivery of hydrophilic biomolecules, and as an alternative chemotherapeutic compound against aggressive types of cancer.

Atividade antifúngica do óleo essencial de melaleuca alternifolia sobre leveduras isoladas de candidíase bucal de gestantes HIV positivas / Antifungal activity of melaleuca alternifolia essential oil on yeasts isolated from HIV positive pregnant women with oral candidiasis

A candidíase bucal é a infecção fúngica mais comum em portadores de HIV e, com episódios recorrentes em pacientes com Aids. Com o objetivo de pesquisar novos e eficazes agentes antifúngicos contra cepas resistentes, foi investigada a atividade antifúngica do óleo essencial de Melaleuca alternifolia, em diferentes concentrações, em leveduras isoladas de candidíase oral. O experimento foi realizado por meio da técnica de difusão em ágar. Foram avaliadas cepas padrão de Candida albicans ATCC 10231, Candida tropicalis ATCC 157, Candida glabrata ATCC 30070, Candida krusei ATCC 6258 e Candida dubliniensis ATCC 778157e os isolados da cavidade bucal de gestantes HIV positivas, sendo sete C. albicans, um C. tropicalis, um C.glabrata e um C. krusei. O óleo essencial foi analisado nas quantidades de 20 e 50 μL, nas concentrações de 10 a 100%, variando de 10 em 10%. Todas as cepas analisadas foram suscetíveis ao óleo essencial de M.alternifolia nas concentrações de 70% e 50 %, respectivamente, nos volumes de 20 μL e 50 μL. O potencial antifúngico do óleo essencial de M. alternifolia desperta interesse para o desenvolvimento de novos fármacos.

Oral candidiasis is a fungal infection mostly common in people infected with HIV and the recurrent episodes occur in patients with AIDS. Aiming at searching, a new and efficacious drug against resistant strains, the antifungal activity of essential oil from Melaleuca alternifolia at different concentrations was assessed on yeasts isolated from oral candidiasis. The experiment was performed by using agar diffusiontechnique; and the antifungal effect was evaluated on the standard strains of Candida albicans ATCC 10231, Candida tropicalis ATCC 157, Candida glabrata ATCC 30070, Candida krusei ATCC 6258 and Candida dubliniensis ATCC 778 157, and on the isolated from the oral cavity of HIV positive pregnant women, being seven C. albicans, one C. tropicalis, one C glabrata and one C. krusei. The essential oil was analyzedin quantities of 20 and 50 μL at 10-100% concentrations, ranging from 10 to 10%. All of the tested strainswere susceptible to the M. alternifolia essential oil at concentrations of 70% and 50% in volumes of 20 μL and 50 μL, respectively. The antifungal activity of essential oil from M. alternifolia holds one´s attention in manufacturing new and effective drugs.

Atividade antifúngica do óleo essencial de Cymbopogon citratus frente a cepas de Candida albicans e Candida tropicalis isoladas de infecções nosocomiais / Antifungal activity of Cymbopogon citratus essential oil on Candida albicans and Candida tropicalis strains isolated from nosocomial infections

O óleo essencial de Cymbopogon citratus tem sido alvo de vários estudos em função do potencial antimicrobiano. Neste estudo, a atividade desse componente foi investigada em cepas do gênero Candida isoladas de infecções hospitalares. Para a condução do estudo, foram analisadas 24 isolados de Candida albicans e 15 isolados de Candida tropicalis, originados de pacientes com suspeitas de infecção hospitalar e uma cepa padrão de C. albicans ATCC 10231, por meio da técnica de difusão em ágar. O óleo essencial de C. citratus apresentou atividade antifúngica em 100% dos isolados a partir da concentração de 25% (v/v), o que indica sua ação positiva sobre as cepas hospitalares. Sugere-se a realização de estudos farmacológicos e toxicológicos desse componente para avaliar a possível aplicação clínica.

Atividade antifúngica do citral em leveduras do gênero Candida isoladas de pacientes hospitalizados / Citral antifungal activity against Candida genus yeasts isolated from hospitalized patients

O citral, componente do óleo essencial de Cymbopogon citratus, tem sido pesquisado para verificar sua ação antimicrobiana em bactérias e fungos. Com o objetivo de avaliar a atividade antifúngica do citral contra leveduras do gênero Candida, no presente trabalho foram avaliadas 32 amostras de Candida albicans, 25 de C. tropicalis, 20 de C. parapsilosis e 5 de C. glabrata, coletadas de pacientes hospitalizados. O citral foi testado nas concentrações de 10%, 15%, 25%, 35%, 50% e 60% (v/v), utilizando a técnica de difusão em ágar Sabouraud. A atividade antifúngica do citral foi constatada em todas as leveduras selecionadas nas concentrações ≥25%. Mediante os resultados obtidos, sugere-se a realização de novas pesquisas sobre citral frente às demais espécies de fungos patogênicos para conhecer as características toxicológicas e farmacológicas para que esse componente possa futuramente ser utilizado como um importante princípio ativo na produção de novos agentes antifúngicos.