DICER ACTIVATION REDUCES LPS-INDUCED PROINFLAMMATORY PATHOLOGICAL REMODELING OF ASTROCYTES IN VITRO

DONNA S; VILLARREAL A; MURTA V; AJ RAMOS

Congreso; Reunión anual de sociedades de biociencias 2021. Sociedad Argentina de Investigaciones Clínicas; 2021

Sociedad Argentina de Investigación Clínica (SAIC)

Astrocytes undergo molecular and morphological changes in responseto acute injury or chronic pathologies of the Central NervousSystem (CNS) in a process called reactive gliosis. Reactiveastrocytes may suffer a pathological remodeling with proinflammatorygain-of-function that facilitates neurodegeneration. Strategies toprevent this conversion are important to prevent secondary neuronaldeath in different CNS pathologies. Repurposed drugs such as Metforminand Enoxacin have shown neuroprotective effects in differentexperimental models and, although their mechanisms of action arevery different, they share the ability to induce miRNA processingenzyme Dicer. Here, we pre-incubated primary glial mixed culturescontaining astrocytes and microglia for 24 h with Metformin (MET,10-30 mM) or Enoxacin (ENO, 50 μM), and then we exposed themto 25 ng/ml Lipopolissacharide (LPS), a molecule that is a powerfulinducer of astroglial pathological remodeling. Astroglial and microglialmorphology were analyzed at 6 and 24 h using immunofluorescencemicroscopy and Image analysis. Nuclear localizationof the p65 NFKB subunit was evaluated as a parameter of NFKBactivation by immunostaining (p65/GFAP/DAPI or p65/Iba-1/DAPI).Our results showed that 30 mM MET or 50 μM ENO significantlydecreased LPS-induced NFKB activation and reduced reactive gliosisin this in vitro paradigm. Although the effect was significative inboth astrocytes and microglia, astrocytes showed a trend to be moresensitive to MET and ENO effects. Expression of proinflammatorycytokines (IL-1B, TNFa) was also significantly reduced by METtreatment. Although the detailed molecular mechanisms involvedhave not been elucidated yet, we speculate increased Dicer activityis probably expanding the repertoire of astroglial anti-inflammatorymiRNA and future work will attempt to identify these miRNA expandedby MET and ENO treatments. Supported by grants PICT 2019-0851; PICT 2017-2203; UBACYT; PIP CONICET