Lactate: an alternative pathway for the immunosuppressive properties of mesenchymal stem/stromal cells.

Background: The metabolic reprogramming of mesenchymal stem/stromal cells (MSC) favoring glycolysis has recently emerged as a new approach to improve their immunotherapeutic abilities. This strategy is associated with greater lactate release, and interestingly, recent studies have proposed lactate as a functional suppressive molecule, changing the old paradigm of lactate as a waste product. Therefore, we evaluated the role of lactate as an alternative mediator of MSC immunosuppressive properties and its contribution to the enhanced immunoregulatory activity of glycolytic MSCs.

Neuroprotective and Neurotoxic Effects of Glial-Derived Exosomes.

Exosomes derived from glial cells such as astrocytes, microglia, and oligodendrocytes can modulate cell communication in the brain and exert protective or neurotoxic effects on neurons, depending on the environmental context upon their release. Their isolation, characterization, and analysis under different conditions , in animal models and samples derived from patients has allowed to define the participation of other molecular mechanisms behind neuroinflammation and neurodegeneration spreading, and to propose their use as a potential diagnostic tool. Moreover, the discovery of specific molecular cargos, such as cytokines, membrane-bound and soluble proteins (neurotrophic factors, growth factors, misfolded proteins), miRNA and long-non-coding RNA, that are enriched in glial-derived exosomes with neuroprotective or damaging effects, or their inhibitors can now be tested as therapeutic tools.