Abstract
Objectives To assess various neuroinflammatory gene expressions in temporal lobe samples from patients with drug-resistant temporal lobe epilepsy (DRTLE).
Methods We used a BioMark Fluidigm custom made microarray chip to analyse a panel of 38 selected genes and 10 housekeeping genes. RNA was isolated from frozen temporal brain samples from 20 DRTLE patients and 12 non-epilepsy post-mortem controls. 1uG of RNA was converted to cDNA. 100ng of cDNA was used for qPCR performed in collaboration with the Monash Health Translation Precinct, Australia. Unpaired t-test and Mann-Whitney tests were used for comparisons of parametric and non-parametric data, respectively. Significance was set at p<0.05.
Results Several genes related to inflammasome and proinflammatory pathways were upregulated in DRTLE compared to controls: NLRP3, CASP1, TNF, IL1B, IL18; as were several chemokines (CCL2, CCL3, CXCL9). Genes encoding monocyte/macrophage/microglia markers (CD14, CD68) were also elevated in patients, however P2X7R was not. While the general leukocyte marker CD45 was elevated in patients, lymphocyte related markers and cytokines such as BAFF (B-cell-activating factor) and IL17B (Th17 response) were decreased. Th2/Th1 pathway related genes (IL4, IL2, IL5, IL13, IL15 and IFNG, CXCL10, IL12) were similar between cohorts. Interestingly, IL6 levels were similar between the two cohorts, and ‘anti-inflammatory’ genes IL1RN, TGFB1, IL10 were upregulated in patients. Astrocytosis marker GFAP was not differentially expressed between cohorts.
Conclusions Brain tissue from DRTLE patients harbours elevations in various markers of neuroinflammation – in particular those of inflammasome and innate immunity pathways. This highlights a possible role of innate immunity in DRTLE pathogenesis.
