RESUMO
BACKGROUND AND AIMS: Inflammatory bowel diseases [IBD] represent a challenging health issue with a complex aetiology involving genetic and environmental parameters. Although our understanding of the pathophysiology of IBD has improved, much remains to be explored. In this context, bioactive lipids, more specifically oxysterols, i.e. oxygenated derivatives of cholesterol, represent an interesting avenue to investigate. Indeed, oxysterols or their receptors are involved in inflammation and immune regulation. Therefore, we set out to study the oxysterome in IBD. METHODS: We used both high-performance liquid chromatograph/mass spectroscopy and molecular biology tools to quantify oxysterol levels and the expression of their metabolic enzymes in several models of murine colitis [both acute and chronic], as well as in colon biopsies from patients with Crohn's disease and ulcerative colitis. RESULTS: We found that the oxysterome is altered in IBD, in both acute and chronic murine models as well as in human IBD. Two of the oxysterols quantified, 4ß-hydroxycholesterol and 25-hydroxycholesterol, were consistently altered in all our models and therefore could be of interest in this context. Hence, we administered them to mice with colitis. While 25-hydroxycholesterol had no effect, 4ß-hydroxycholesterol worsened colon inflammation. CONCLUSIONS: Our study addresses the potential involvement of oxysterols in colitis and clearly points towards an active role as well as a clinical relevance for these bioactive lipids.
Assuntos
Colite Ulcerativa/metabolismo , Colite/metabolismo , Colo/metabolismo , Doença de Crohn/metabolismo , Hidroxicolesteróis/farmacologia , Oxisteróis/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Colite Ulcerativa/patologia , Colo/química , Colo/efeitos dos fármacos , Colo/patologia , Doença de Crohn/patologia , Modelos Animais de Doenças , Humanos , Fígado/química , Masculino , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos C57BL , Oxisteróis/análise , Oxisteróis/sangue , Peroxidase/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , TranscriptomaRESUMO
Lysophosphatidylinositols (LPI) are bioactive lipids that are implicated in several pathophysiological processes such as cell proliferation, migration and tumorigenesis and were shown to play a role in obesity and metabolic disorders. Often, these effects of LPI were due to activation of the G protein-coupled receptor GPR55. However, the role of LPI and GPR55 in inflammation and macrophage activation remains unclear. Therefore, we thought to study the effect of macrophage activation and inflammation on LPI levels and metabolism. To do so, we used J774 and BV2 cells in culture activated with lipopolysaccharides (LPS, 100â¯ng/mL) as well as primary mouse alveolar and peritoneal macrophages. We also quantified LPI levels in the cerebellum, lung, liver, spleen and colon of mice with a systemic inflammation induced by LPS (300⯵g/kg) and in the colon of mice with acute colitis induced by dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS) and chronic DSS-induced colitis. Our data show that LPS-induced macrophage activation leads to altered LPI levels in both the cells and culture medium. We also show that cytosolic phospholipase A2α (cPLA2α) and α/ßhydrolase domain 6 (ABHD6) are among the enzymes implicated in LPI metabolism in J774 macrophages. Indeed, ABHD6 and cPLA2α inhibition increased 20:4-LPI levels in LPS-activated macrophages. Furthermore, incubation of LPS-activated cells with LPI decreased J774 activation in a GPR55-dependent manner. In vivo, LPI levels were altered by inflammation in the liver, spleen and colon. These alterations are tissue dependent and could highlight a potential role for LPI in inflammatory processes.
Assuntos
Colite/metabolismo , Sulfato de Dextrana/efeitos adversos , Lipopolissacarídeos/efeitos adversos , Lisofosfolipídeos/metabolismo , Macrófagos/efeitos dos fármacos , Ácido Trinitrobenzenossulfônico/efeitos adversos , Animais , Linhagem Celular , Colite/induzido quimicamente , Colo/metabolismo , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Fosfolipases A2 do Grupo IV/metabolismo , Fígado/metabolismo , Macrófagos/citologia , Macrófagos/metabolismo , Masculino , Camundongos , Monoacilglicerol Lipases/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Baço/metabolismo , Distribuição TecidualRESUMO
Secondary damage following spinal cord injury leads to non-reversible lesions and hampering of the reparative process. The local production of pro-inflammatory cytokines such as TNF-α can exacerbate these events. Oligodendrocyte death also occurs, followed by progressive demyelination leading to significant tissue degeneration. Dental stem cells from human apical papilla (SCAP) can be easily obtained at the removal of an adult immature tooth. This offers a minimally invasive approach to re-use this tissue as a source of stem cells, as compared to biopsying neural tissue from a patient with a spinal cord injury. We assessed the potential of SCAP to exert neuroprotective effects by investigating two possible modes of action: modulation of neuro-inflammation and oligodendrocyte progenitor cell (OPC) differentiation. SCAP were co-cultured with LPS-activated microglia, LPS-activated rat spinal cord organotypic sections (SCOS), and LPS-activated co-cultures of SCOS and spinal cord adult OPC. We showed for the first time that SCAP can induce a reduction of TNF-α expression and secretion in inflamed spinal cord tissues and can stimulate OPC differentiation via activin-A secretion. This work underlines the potential therapeutic benefits of SCAP for spinal cord injury repair.
Assuntos
Ativinas/metabolismo , Diferenciação Celular/fisiologia , Papila Dentária/metabolismo , Inflamação/prevenção & controle , Células Precursoras de Oligodendrócitos/metabolismo , Células-Tronco/metabolismo , Adulto , Animais , Linhagem Celular , Doenças Desmielinizantes/metabolismo , Doenças Desmielinizantes/prevenção & controle , Papila Dentária/citologia , Humanos , Inflamação/metabolismo , Camundongos , Neurônios/metabolismo , Oligodendroglia/metabolismo , Ratos , Ratos Wistar , Medula Espinal/metabolismo , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/terapia , Células-Tronco/citologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Tumors use tryptophan-catabolizing enzymes such as indoleamine 2,3-dioxygenase (IDO-1) to induce an immunosuppressive environment. IDO-1 is induced in response to inflammatory stimuli and promotes immune tolerance through effector T-cell anergy and enhanced Treg function. As such, IDO-1 is a nexus for the induction of a key immunosuppressive mechanism and represents an important immunotherapeutic target in oncology. Starting from HTS hit 5, IDO-1 inhibitor 6 (EOS200271/PF-06840003) has been developed. The structure-activity relationship around 6 is described and rationalized using the X-ray crystal structure of 6 bound to human IDO-1, which shows that 6, differently from most of the IDO-1 inhibitors described so far, does not bind to the heme iron atom and has a novel binding mode. Clinical candidate 6 shows good potency in an IDO-1 human whole blood assay and also shows a very favorable ADME profile leading to favorable predicted human pharmacokinetic properties, including a predicted half-life of 16-19 h.