A key role of the mitochondrial Translocator Protein 18 KDa (TSPO) in neuroinflammation has been recently proposed. However, little is known about TSPO-activated pathways underlying the modulation of reactive microglia. In the present work, the TSPO activation was explored in an in vitro human primary microglia model (immortalized C20 cells) under inflammatory stimulus. Two different approaches were used with the aim to (i) pharmacologically amplify or (ii) silence, by the lentiviral short hairpin RNA, the TSPO physiological function. In the TSPO pharmacological stimulation model, the synthetic steroidogenic selective ligand XBD-173 attenuated the activation of microglia. Indeed, it reduces and increases the release of pro-inflammatory and anti-inflammatory cytokines, respectively. Such ligand-induced effects were abolished when C20 cells were treated with the steroidogenesis inhibitor aminoglutethimide. This suggests a role for neurosteroids in modulating the interleukin production. The highly steroidogenic ligand XBD-173 attenuated the neuroinflammatory response more effectively than the poorly steroidogenic ones, which suggests that the observed modulation on the cytokine release may be influenced by the levels of produced neurosteroids. In the TSPO silencing model, the reduction of TSPO caused a more inflamed phenotype with respect to scrambled cells. Similarly, during the inflammatory response, the TSPO silencing increased and reduced the release of pro-inflammatory and anti-inflammatory cytokines, respectively. In conclusion, the obtained results are in favor of a homeostatic role for TSPO in the context of dynamic balance between anti-inflammatory and pro-inflammatory mediators in the human microglia-mediated inflammatory response. Interestingly, our preliminary results propose that the TSPO expression could be stimulated by NF-κB during activation of the inflammatory response.

Therapies that target the signal transduction and metabolic pathways of cancer stem cells (CSCs) are innovative strategies to effectively reduce the recurrence and significantly improve the outcome of glioblastoma multiforme (GBM). CSCs exhibit an increased rate of glycolysis, thus rendering them intrinsically more sensitive to prospective therapeutic strategies based on the inhibition of the glycolytic pathway. The enzyme lactate dehydrogenase-A (LDH-A), which catalyses the interconversion of pyruvate and lactate, is up-regulated in human cancers, including GBM. Although several papers have explored the benefits of targeting cancer metabolism in GBM, the effects of direct LDH-A inhibition in glial tumours have not yet been investigated, particularly in the stem cell subpopulation. Here, two representative LDH-A inhibitors (NHI-1 and NHI-2) were studied in GBM-derived CSCs and compared to differentiated tumour cells. LDH-A inhibition was particularly effective in CSCs isolated from different GBM cell lines, where the two compounds blocked CSC formation and elicited long-lasting effects by triggering both apoptosis and cellular differentiation. These data demonstrate that GBM, particularly the stem cell subpopulation, is sensitive to glycolytic inhibition and shed light on the therapeutic potential of LDH-A inhibitors in this tumour type.

Neurodegenerative disorders (NDs) are characterized by abnormal accumulation/misfolding of specific proteins, primarily α-synuclein (α-syn), β-amyloid_1–42 (Aβ_1–42) and tau, in both brain and peripheral tissues. In addition to oligomers, the role of the interactions of α-syn with Aβ or tau has gradually emerged. Nevertheless, despite intensive research, NDs have no accepted peripheral markers for biochemical diagnosis. In this respect, Red Blood Cells (RBCs) are emerging as a valid peripheral model for the study of aging-related pathologies. Herein, a small cohort (N = 28) of patients affected by Parkinson’s disease (PD) and age-matched controls were enrolled to detect the content of α-syn (total and oligomeric), Aβ_1–42 and tau (total and phosphorylated) in RBCs. Moreover, the presence of α-syn association with tau and Aβ_1–42 was explored by co-immunoprecipitation/western blotting in the same cells, and quantitatively confirmed by immunoenzymatic assays. For the first time, PD patients were demonstrated to exhibit α-syn heterocomplexes with Aβ_1–42 and tau in peripheral tissues; interestingly, α-syn-Aβ_1–42 concentrations were increased in PD subjects with respect to healthy controls (HC), and directly correlated with disease severity and motor deficits. Moreover, total-α-syn levels were decreased in PD subjects and inversely related to their motor deficits. Finally, an increase of oligomeric-α-syn and phosphorylated-tau was observed in RBCs of the enrolled patients. The combination of three parameters (total-α-syn, phosphorylated-tau and α-syn-Aβ_1–42 concentrations) provided the best fitting predictive index for discriminating PD patients from controls. Nevertheless further investigations should be required, overall, these data suggest α-syn hetero-aggregates in RBCs as a putative tool for the diagnosis of PD.

In the complex scenario of cancer, treatment with compounds targeting multiple cell pathways has been emerging. In Glioblastoma Multiforme (GBM), p53 and Translocator Protein (TSPO), both acting as apoptosis inducers, represent two attractive intracellular targets. On this basis, novel indolylglyoxylyldipeptides, rationally designed to activate TSPO and p53, were synthesized and biologically characterized. The new compounds were able to bind TSPO and to reactivate p53 functionality, through the dissociation from its physiological inhibitor, murine double minute 2 (MDM2). In GBM cells, the new molecules caused Δψm dissipation and inhibition of cell viability. These effects resulted significantly higher with respect to those elicited by the single target reference standards applied alone and coherent with the synergism resulting from the simultaneous activation of TSPO and p53. Taken together, these results suggest that TSPO/MDM2 dual-target ligands could represent a new attractive multi-modal opportunity for anti-cancer strategy in GBM.