MIF homolog d-dopachrome tautomerase (D-DT/MIF-2) does not inhibit accumulation and toxicity of misfolded SOD1

The Role of Macrophage Migration Inhibitory Factor (MIF) and D-Dopachrome Tautomerase (D-DT/MIF-2) in Infections: A Clinical Perspective

Macrophage migration inhibitory factor (MIF) and its homolog, D-dopachrome tautomerase (D-DT), are cytokines that play critical roles in the immune response to various infectious diseases. This review provides an overview of the complex involvement of MIF and D-DT in bacterial, viral, fungal, and parasitic infections. The role of MIF in different types of infections is controversial, as it has either a protective function or a host damage-enhancing function depending on the pathogen. Depending on the specific role of MIF, different therapeutic options for MIF-targeting drugs arise. Human MIF-neutralizing antibodies, anti-parasite MIF antibodies, small molecule MIF inhibitors or MIF-blocking peptides, as well as the administration of exogenous MIF or MIF activity-augmenting small molecules have potential therapeutic applications and need to be further explored in the future. In addition, MIF has been shown to be a potential biomarker and therapeutic target in sepsis. Further research is needed to unravel the complexity of MIF and D-DT in infectious diseases and to develop personalized therapeutic approaches targeting these cytokines. Overall, a comprehensive understanding of the role of MIF and D-DT in infections could lead to new strategies for the diagnosis, treatment, and management of infectious diseases.

Protective effects of EVs/exosomes derived from permanently growing human MSC on primary murine ALS motor neurons

In recent years, the neuroprotective potential of mesenchymal stroma-/stem-like cells (MSC) as well as of MSC-derived extracellular vesicles (EVs) like exosomes has been intensively explored. This included preclinical evaluation regarding treatment of neurodegenerative disorders such as the fatal motor neuron disease amyotrophic Lateral Sclerosis (ALS). Several studies have reported that MSC-derived exosomes can stimulate tissue regeneration and reduce inflammation. MSC release EVs and trophic factors and thereby modify cell-to-cell communication. These cell-free products may protect degenerating motor neurons (MNs) and represent a potential therapeutic approach for ALS. In the present study we investigated the effects of exosomes derived from a permanently growing MSC line on both, wild type and ALS (SOD1G93A transgenic) primary motor neurons. Following application in a normal and stressed environment we could demonstrate beneficial effects of MSC exosomes on neurite growth and morphology indicating the potential for further preclinical evaluation and clinical therapeutic development. Investigation of gene expression profiles detected transcripts of several antioxidant and anti-inflammatory genes in MSC exosomes. Characterization of their microRNA (miRNA) content revealed miRNAs capable of regulating antioxidant and anti-apoptotic pathways.

Macrophage migration inhibitory factor (MIF) and its homolog D-dopachrome tautomerase (D-DT) are significant promotors of UVB- but not chemically induced non-melanoma skin cancer

Non-melanoma skin cancer (NMSC) is the most common cancer in Caucasians worldwide. We investigated the pathophysiological role of MIF and its homolog D-DT in UVB- and chemically induced NMSC using Mif-/-, D-dt-/- and Mif-/-/D-dt-/- mice on a hairless SKH1 background. Knockout of both cytokines showed similar attenuating effects on inflammation after acute UVB irradiation and tumor formation during chronic UVB irradiation, without additive protective effects noted in double knockout mice, indicating that both cytokines activate a similar signaling threshold. In contrast, genetic deletion of Mif and D-dt had no major effects on chemically induced skin tumors. To get insight into the contributing mechanisms, we used an in vitro 3D skin model with incorporated macrophages. Application of recombinant MIF and D-DT led to an accumulation of macrophages within the epidermal part that could be reversed by selective inhibitors of MIF and D-DT pathways. In summary, our data indicate that MIF and D-DT contribute to the development and progression of UVB- but not chemically induced NMSC, a role at least partially accounted by effects of both cytokines on epidermal macrophage accumulation. These data highlight that MIF and D-DT are both potential therapeutic targets for the prevention of photocarcinogenesis but not chemical carcinogenesis.