The Long-Term Neuroprotective Effect of the Endocannabinoid 2-AG and Modulation of the SGZ’s Neurogenic Response after Neonatal Hypoxia-Ischemia

Neonatal hypoxia-ischemia (HI) often causes hypoxic-ischemic encephalopathy (HIE), a neurological condition that can lead to overall disability in newborns. The only treatment available for affected neonates is therapeutic hypothermia; however, cooling is not always effective to prevent the deleterious effects of HI, so compounds such as cannabinoids are currently under research as new therapies. Modulating the endocannabinoid system (ECS) may reduce brain damage and/or stimulate cell proliferation at the neurogenic niches. Further, the long-term effects of cannabinoid treatment are not so clear. Here, we studied the middle- and long-term effects of 2-AG, the most abundant endocannabinoid in the perinatal period after HI in neonatal rats. At middle-term (postnatal day 14), 2-AG reduced brain injury and increased SGZ’s cell proliferation and the number of neuroblasts. At post-natal day 90, the treatment with the endocannabinoid showed global and local protection, suggesting long-lasting neuroprotective effects of 2-AG after neonatal HI in rats.This research was funded by EITB Maratoia-BIOEF, grant BIO18/IC/003, by MCIN/AEI/10.13039/501100011033, grant MINECOR20/P66 and by the “Programa Investigo” by the European Union-Next Generation EU, grant PIFINVE22/15

Magnesium Sulfate Treatment Decreases the Initial Brain Damage Alterations Produced After Perinatal Asphyxia in Fetal Lambs

The aim of this work was to analyze the effect of MgSO4 treatment in the brain after hypoxic–ischemic (HI) injury in premature fetal lambs. Injury was induced by partial occlusion of umbilical cord for 60 min, and then the preterm lambs (80–90% of gestation) were randomly assigned to one of the following groups: control group, in which the animals were managed by conventional mechanical ventilation for 3 hr; 3 hr postpartial cord occlusion (3-hr-PCO) group, in which injured animals were managed by ventilation and then sacrificed 3 hr after HI; and MgSO4 group, in which animals received 400 mg/kg MgSO4 for 20 min soon after HI was induced and were managed by ventilation for 3 hr. Brains were analyzed for apoptosis by TUNEL assay. Cell viability and intracellular state studies were assessed by flow cytometry. The delayed death index was significantly increased in the 3-hr-PCO group in comparison with control. Administration of MgSO4elicited a delay in cell death that was similar to that in the control group. The 3-hr-PCO group showed a significantly higher concentration of reactive oxygen species, mitochondrial damage, and intracellular calcium in comparison with control and MgSO4- treated groups. Our results suggest that MgSO4 treatment might have potential therapeutic benefits after the HI event. © 2012 Wiley Periodicals, Inc

Characterization of phenotype markers and neuronotoxic potential of polarised primary microglia in vitro

AbstractMicroglia mediate multiple facets of neuroinflammation, including cytotoxicity, repair, regeneration, and immunosuppression due to their ability to acquire diverse activation states, or phenotypes. Modulation of microglial phenotype is an appealing neurotherapeutic strategy but a comprehensive study of classical and more novel microglial phenotypic markers in vitro is lacking. The aim of this study was to outline the temporal expression of a battery of phenotype markers from polarised microglia to generate an in vitro tool for screening the immunomodulatory potential of novel compounds. We characterised expression of thirty-one macrophage/microglial phenotype markers in primary microglia over time (4, 12, 36, and 72h), using RT-qPCR or multiplex protein assay. Firstly, we selected Interleukin-4 (IL-4) and lipopolysaccharide (LPS) as the strongest M1–M2 polarising stimuli, from six stimuli tested. At each time point, markers useful to identify that microglia were M1 included iNOS, Cox-2 and IL-6 and a loss of M2a markers. Markers useful for quantifying M2b-immunomodulatory microglia included, increased IL-1RA and SOCS3 and for M2a-repair and regeneration, included increased arginase-1, and a loss of the M1 and M2b markers were discriminatory. Additional markers were regulated at fewer time points, but are still likely important to monitor when assessing the immunomodulatory potential of novel therapies. Further, to facilitate identification of how novel immunomodulatory treatments alter the functional affects of microglia, we characterised how the soluble products from polarised microglia affected the type and rate of neuronal death; M1/2b induced increasing and M2a-induced decreasing neuronal loss. We also assessed any effects of prior activation state, to provide a way to identify how a novel compound may alter phenotype depending on the stage of injury/insult progression. We identified generally that a prior M1/2b reduced the ability of microglia to switch to M2a. Altogether, we have characterised a profile of phenotype markers and a mechanism of assessing functional outcome that we can use as a reference guide for first-line screening of novel immunomodulatory therapies in vitro in the search for viable neuroprotectants