Urokinase receptor and tissue plasminogen activator as immediate‐early genes in pentylenetetrazole‐induced seizures in the mouse brain

Abstract

Epileptogenesis progressively leads to the rearrangement of normal neuronal networks into more excitable ones and can be viewed as a form of neuroplasticity, the molecular mechanisms of which still remain obscure. Here, we studied pentylenetetrazole seizure-induced regulation of genes for plasminogen activator system in the mouse brain. We found that expression of tissue plasminogen activator (tPA) and urokinase receptor (uPAR) mRNA was strongly increased in the mouse cerebral cortex, hippocampus, striatum and amygdala as early as 3 hr after pentylenetetrazole seizures. Such early activity-induced expression of uPAR in the central nervous system has not been demonstrated before. uPAR mRNA accumulation was followed by elevation of uPAR protein, indicating a complete transcription-translation process.Both tPA gene induction and uPAR gene induction were independent of the protein synthesis, suggesting that they are regulated by neural activity as immediate-early genes. In contrast to tPA and uPAR genes, the expression of which returned to the basal level 6 hr following seizures, urokinase and plasminogen activator inhibitor-1 gene expression showed a delayed activation only at 3 days after seizures. In conclusion, our results suggest an important sensitivity of the brain plasminogen activator system to seizure activity which raises the question of its role in activity-dependent neural tissue remodeling in pathological and normal conditions. 1560 |

Identification of a Novel Small RNA Encoded in the Mouse Urokinase Receptor uPAR Gene (Plaur) and Its Molecular Target Mef2d

“…We had previously shown that Plaur gene expression is induced in various brain structures ( Shmakova et al, 2020 ) in a model of pentylenetetrazole (PTZ)-induced seizures in mice. Here we used miRNA and mRNA isolated from previously obtained brain samples.…”

“…Here we used miRNA and mRNA isolated from previously obtained brain samples. A detailed description of methodology, animal facility and enabling documentation has been previously published ( Shmakova et al, 2020 ). To assess the endogenous level of Plaur-miR1 induction and expression of its target genes, we selected brain regions with the most significant Plaur mRNA induction 3 h after PTZ (Sigma-Aldrich, cat.…”

“…# P6500, Saint Louis, MO, United States) administration. Thus, posterior cortex ( Plaur induction was 8.7 times higher than control) was enrolled to assess the level of Plaur-mir1-5p and Plaur-mir1-3p and the striatum ( Plaur induction was 16 times higher than control)—for the target gene analysis (for further information, see Figure 2 in Shmakova et al, 2020 ).…”

“…Brain tissue samples was homogenized and lysed in an ice-cold RIPA lysis buffer as previously described ( Shmakova et al, 2020 ). Proteins (45 μg) were resolved in 10% SDS-PAGE gels and transferred to PVDF membrane (GE Healthcare) in the transfer buffer (25 mM Tris, 192 mM glycine, 0.1% SDS and 20% methanol).…”

“…Recent papers have shown that mutations and polymorphisms in the Plaur gene or uPAR ligand SRPX2 affect the formation of brain structures and induce severe developmental pathologies in humans (speech deficiency, mental weakness and autism spectrum disorders) ( Bruneau and Szepetowski, 2011 ). Using a model of acute generalized seizures in mice, we revealed that Plaur operates as an immediate early gene, and is rapidly induced by neuronal activity in different brain regions independently of de novo protein synthesis ( Shmakova et al, 2020 ). This rapid and universal response confirms an important role of uPAR in neuronal response to excitation and/or damage.…”