Analysis of Secreted MIF from Cultured Murine Bone Marrow-Derived Immune Cells

Macrophage migration inhibitory factor (MIF) is expressed and released ubiquitously by numerous cell types and tissues. MIF is detected and constitutively expressed at the protein level both intra- and extracellularly. This chapter outlines methods for cultivating, purifying, detecting, and quantifying concentrations of MIF from murine primary derived macrophages and dendritic cell culture supernatants.

Flow Cytometry Phenotyping of Bone Marrow-Derived Macrophages from Wild-Type and Mif-/- Mice

Phenotyping cells by flow cytometry is a powerful way to identify cell type and any morphological changes during cell culture. The staining procedure used in this chapter enables the characterization of mouse macrophages by a flow cytometry antibody panel which can be used for both bone marrow-derived macrophages (BMM) and macrophages derived from other tissues, such as the mouse spleen or peritoneal cavity. The surface and intracellular staining methods are versatile and can be applied to flow cytometry staining of several different cell types by changing the surface markers used with knowledge of which receptors are expressed on different cell types.

The involvement of Kav001 in inhibition of LPS/P. gingivalis-induced

TNF-a is an important cytokine mediator of inflammation which suggests that inhibition of TNF activity may provide potential for clinical application. Recent data indicated that treatment of both human and mouse cells with Kavain significantly modulates P. gingivalis- and LPS-induced TNF-α expression. In order to obtain a selective analog with optimized biological activity and structural physico-chemical properties of Kavain, Kavain analogs were designed and synthesized and found one Kavain analogue (named Kav001) that is similar to Kavain but soluble and does not induce a significant toxicity. Both studies in vitro and in vivo treatment by Kav001 showed stronger biological function as compared to Kavain. Furthermore, most mouse bone marrow macrophages up-regulated Bcl-6 while down-regulating LITAF expression after treatment with Kav001 for 36 h. Consequently, this led to an extension of macrophage pseudopods due to its immune response to P.g. infection/LPS stimulation.

Influence of Bone Marrow Microenvironment on Leukemic Stem Cells: Breaking Up an Intimate Relationship

The bone marrow microenvironment (BMM) plays a critical role in hematopoietic stem cells (HSCs) maintenance and regulation. There is increasing interest in the role of the BMM in promoting leukemia stem cell (LSC) maintenance, resistance to conventional chemotherapy and targeted therapies, and ultimately disease relapse. Recent studies have enhanced our understanding of how the BMM regulates quiescence, self-renewal, and differentiation of LSC. In this comprehensive review, we discuss recent advances in our understanding of the crosstalk between the BMM and LSC, and the critical signaling pathways underlying these interactions. We also discuss potential approaches to exploit these observations to create novel strategies for targeting therapy-resistant LSC to achieve relapse-free survival in leukemic patients.

Nrf2 deficiency induces oxidative stress and promotes RANKL-induced osteoclast differentiation

Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a redox-sensitive transcription factor that regulates the expression of a variety of antioxidant and detoxification genes through an antioxidant-response element. Nrf2 has been shown to protect several types of cells against the acute and chronic injury that accompanies oxidative stress, but its role in osteoclasts remains unclear. In this study, we investigated the role of Nrf2 in osteoclast (OC) differentiation, a process in which reactive oxygen species (ROS) are generated and then participate, using Nrf2-knockout mice. Receptor activator of nuclear factor κB ligand (RANKL)-induced OC differentiation, actin ring formation, and osteoclastic bone resorption were substantially promoted in Nrf2-deficient OC precursor cells compared to wild-type cells. Under both unstimulated and RANKL-stimulated conditions, Nrf2 loss led to an increase in the intracellular ROS level and the oxidized-to-reduced glutathione ratio and a defect in the production of numerous antioxidant enzymes and glutathione. Moreover, pretreatment with N-acetylcysteine or diphenyleneiodonium significantly reduced the OC differentiation and decreased the intracellular ROS level in both Nrf2-deficient and wild-type cells. Pretreatment with sulforaphane and curcumin also inhibited the OC differentiation by activating Nrf2 in part. Nrf2 deficiency promoted the RANKL-induced activation of mitogen-activated protein kinases, including c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38; the induction of c-Fos; and the consequent induction of nuclear factor of activated T cells, cytoplasmic 1, a pivotal determinant of OC differentiation. Our results suggest that Nrf2 probably inhibits RANKL-induced OC differentiation by regulating the cellular redox status by controlling the expression of oxidative response genes, findings that might form the basis of a new strategy for treating inflammatory bone diseases.

Systems biology of host-mycobiota interactions: dissecting Dectin-1 and Dectin-2 signalling in immune cells with DC-ATLAS

Modelling the networks sustaining the fruitful coexistence between fungi and their mammalian hosts is becoming increasingly important to control emerging fungal pathogens. The C-type lectins Dectin-1 and Dectin-2 are involved in host defense mechanisms against fungal infection driving inflammatory and adaptive immune responses and complement in containing fungal burdens. Recognizing carbohydrate structures in pathogens, their engagement induces maturation of dendritic cells (DCs) into potent immuno-stimulatory cells endowed with the capacity to efficiently prime T cells. Owing to these properties, Dectin-1 and Dectin-2 agonists are currently under investigation as promising adjuvants in vaccination procedures for the treatment of fungal infection. Thus, a detailed understanding of events' cascade specifically triggered in DCs upon engagement is of great interest in translational research. Here, we summarize the current knowledge on Dectin-1 and Dectin-2 signalling in DCs highlighting similarities and differences. Detailed maps are annotated, using the Biological Connection Markup Language (BCML) data model, and stored in DC-ATLAS, a versatile resource for the interpretation of high-throughput data generated perturbing the signalling network of DCs.