Distinctive Under-Expression Profile of Inflammatory and Redox Genes in the Blood of Elderly Patients with Cardiovascular Disease

Abstract

Purpose: Chronic low-grade inflammation and oxidative stress are present in most of the pathologic mechanisms underlying non-communicable diseases. Inflammation and redox biomarkers might therefore have a value in disease prognosis and therapy response. In this context, we performed a case-control study for assessing in whole blood the expression profile of inflammation and redox-related genes in elderly subjects with various comorbidities.

Patients and methods: In the blood of 130 elderly subjects with various pathologies (cardiovascular disease, hypertension, dyslipidemia including hypercholesterolemia, type 2 diabetes mellitus), kept under control by polyvalent disease-specific medication, we investigated by pathway-focused qRT-PCR a panel comprising 84 inflammation-related and 84 redox-related genes.

Results: The study highlights a distinctive expression profile of genes critically involved in NF-κB-mediated inflammation and redox signaling in the blood of patients with cardiovascular disease, characterized by significant down-regulation of the genes NFKB2, NFKBIA, RELA, RELB, AKT1, IRF1, STAT1, CD40, LTA, TRAF2, PTGS1, ALOX12, DUOX1, DUOX2, MPO, GSR, TXNRD2, HSPA1A, MSRA, and PDLIM1. This gene expression profile defines the transcriptional status of blood leukocytes in stable disease under medication control, without discriminating between disease- and therapy-related changes.

Conclusion: The study brings preliminary proof on a minimally invasive strategy for monitoring disease in patients with cardiovascular pathology, from the point of view of inflammation or redox dysregulation in whole blood.

Keywords: NF-κB signaling; aging-related diseases; cardiovascular disease; inflammation; oxidative stress; redox metabolism.

Figure 1

Classification of the 130 recruited elderly patients in case and control groups, according to comorbidities (CVD-cardiovascular diseases, HT-hypertension, DL-dyslipidemia, HC-hypercholesterolemia, T2DM- Type 2 diabetes mellitus). The subjects presenting a type of comorbidity constituted the case group, while all the other subjects in the cohort, not presenting that specific comorbidity, constituted the control group (C).

Figure 2

Inflammation-related genes differentially expressed in the blood of 39 CVD patients versus 91 controls. The reported genes are involved in: (A) NF-kB signaling, (B) Other signaling pathways, (C) Receptor-mediated signaling, (D) Metabolism of arachidonic acid. Gene expression levels are expressed as mean relative fold of change versus controls and standard error of the mean (SEM). The p-value was calculated using the Mann–Whitney U-test (***p<0.001).

Figure 3

Redox-related genes differentially expressed in the blood of 39 CVD patients versus 91 controls. The reported genes are involved in: (A) ROS producers, (B) Glutathione and thioredoxin metabolism, (C) Repair of oxidative demage, D. Adapters for cytoskeleton proteins. Gene expression levels are expressed as mean relative fold of change versus control and standard error of the mean (SEM). The p-value was calculated using the Mann–Whitney U-test (**p<0.01; ***p<0.001).

Figure 4

Pearson correlations among inflammation-related gene expression levels in 39 CVD patients (A) and in 91 controls (B). Correlations with p-values < 0.001 and r values > 0.7 (light red: 0.7 < r < 0.8; dark red: r ≥ 0.8) are presented.

Figure 5

Pearson correlations among redox related-gene expression levels in 39 CVD patients (A) and in 91 controls (B). Correlations with p-values < 0.001 and r values > 0.7 (light red: 0.7 < r < 0.8; dark red: r ≥ 0.8) are presented.

Figure 6

Pearson correlations among inflammation- and redox-related gene expression levels in 39 CVD patients (A) and in 91 controls (B). Correlations with p-values < 0.001 and r values > 0.7 (light red: 0.7 < r < 0.8; dark red: r ≥ 0.8) are presented.

Figure 7

Signaling constituents of the canonical (A) and the non-canonical (B) NF-κB pathways that are under-expressed in CVD patients. In (A), the binding of ligands to particular receptors leads to the activation of an IKK complex (IKKα and/or IKKβ catalytic subunits and two IKKγ molecules). This complex phosphorylates IκBα leading to degradation by the proteasome and consequent formation of the transcriptionally-active p50-RelA complex. In (B) the binding of ligands to particular receptors triggers the phosphorylation and processing of p100 (encoded by NFKB2) into the mature p52 protein and subsequent nuclear translocation of the transcriptionally-active RelB-p52 heterodimer. The products of the genes found differentially expressed the present study in the group of patients with CVD are marked with a red circle.