[Micro RNA-155 expression in hemodialysis PBMC]

MicroRNAs (miR) are fragments of non-coding RNA acting at post-transcriptional level, which modulate gene expression, and play a key role in several pathophysiological pathways. The aim of this study is to analyze the expression of miR-155 in basal Peripheral Blood Mononuclear Cells (PBMC) of chronic hemodialysis (HD) patients, before and after standard 4 -hour sessions, and after PHA stimulation compared with PBMC from healthy subjects.

miR-155 was isolated from chronic HD patients' PBMC and from PBMC derived from healthy subjects. Expression levels were quantified with Real-Time PCR; PCR reactions were performed using a specific thermocycler and cycle threshold levels were calculated using dedicated software. Blood samples were taken from HD patients after the long inter-dialytic interval. Data were expressed as MSE and statistical differences were calculated with t-test.

Relative quantity (RQ) of pre-dialysis MiR-155 was 3.770.62 times higher than the control group (P=0,003). There was no significant difference before and after hemodialysis sessions. Pre-dialysis mir-155 RQ in PHA PBMC was 1.790.59 times higher than non stimulated PBMC (P=0.019).

these preliminary data show a significant miR-155 up-regulation of HD PBMC when compared to PBMC from healthy individuals. An additional up-regulation was observed in HD PHA PBMC. Similar miR-155 expression was found in HD PBMC comparing pre and post-hemodialysis sessions.