Background:
Hypertension (HTN) is associated with subclinical target organ damage including cardiac, vascular and kidney injury. The immune system plays a role in hypertension and target organ damage. Activation of T cells has been reported among peripheral blood mononuclear cells (PBMCs) of patients with HTN. MicroRNAs (miRNAs) are crucial post-transcriptional regulators of immune cells. Whether miRNAs play a role in the activation of immune cells in hypertension complicated by target organ damage in humans remains unknown. We aimed to address this question by identifying differentially expressed (DE) miRNAs and their mRNA targets in PBMCs of patients with hypertension complicated or not with metabolic syndrome (MetS) or chronic kidney disease (CKD).
Methods:
Normotensive subjects and patients with hypertension (HTN) associated or not with at least 2 other features of MetS or CKD were studied (n=15-16). PBMCs were isolated from blood, RNA extracted for small and total RNA sequencing (RNA-seq) using Illumina HiSeq-2500 and data were analyzed using a systems biology approach. MiRDeep2 was used for novel miRNAs prediction, miRNA annotation and counting. TargetScan 7.07 was used to predict DE miRNA targets with weighted context score percentile >50%. DE genes miRNAs and mRNAs were identified with fold change (FC) >1.5 and
P
<0.005. DE miRNAs with FC>2 and mean read count number (MRCM) >500, and with predicted targets with MRCM>300 were validated by reverse transcription-quantitative PCR (RT-qPCR).
Results:
DE miRNAs, mRNAs and non-coding RNAs were identified in HTN (22, 19 and 0), MetS (57, 401 and 11) and CKD (6, 26 and 2) compared to NTN. TargetScan predicted that 7 miRNAs target 3 mRNAs in NTN, 57 miRNAs target 55 mRNAs in MetS and 3 miRNAs target 2 mRNAs in CKD. DE miR-409-5p (FC: 0.54±0.10 vs 1.00±0.09,
P
<0.05), miR-411-5p (FC: 0.40±0.06, vs 1.00±0.11,
P
<0.001) and the novel miR-pl-86 (FC: 1.96±0.17 vs 1.00±0.15,
P
<0.05) in MetS vs NTN were validated by RT-qPCR. RNA-seq data were correlated with RT-qPCR for miR-409-5p (R
2
=0.40,
P
<2.4E-07, n=55), miR-411-5p (R
2
=0.55,
P
<1.1E-10, n=55), miR-pl-86 (R
2
=0.37,
P
<5.5E-07, n=56).
Conclusion:
This study showed that DE miR-409-5p, miR-411-5p and miR-pl-86 may play a role in HTN associated with MetS.
Target organ damage and metabolic syndrome in non diabetic hypertensive patients
