Effect of 5-Azacitidine Treatment on Redox Status and Inflammatory Condition in MDS Patients

Abstract

This study focused on the impact of the treatment with the hypomethylating agent 5-azacitidine on the redox status and inflammation in 24 MDS patients. Clinical and genetic features of MDS patients were recorded, and peripheral blood samples were used to determine the activity of the endogenous antioxidant defense system (superoxide dismutase, SOD; catalase, CAT; glutathion peroxidase, GPx; and reductase, GRd, activities), markers of oxidative damage (lipid peroxidation, LPO, and advanced oxidation protein products, AOPP). Moreover, pro-inflammatory cytokines and plasma nitrite plus nitrate levels as markers of inflammation, as well as CoQ10 plasma levels, were also measured. Globally, MDS patients showed less redox status in terms of a reduction in the GSSG/GSH ratio and in the LPO levels, as well as increased CAT activity compared with healthy subjects, with no changes in SOD, GPx, and GRd activities, or AOPP levels. When analyzing the evolution from early to advanced stages of the disease, we found that the GPx activity, GSSG/GSH ratio, LPO, and AOPP increased, with a reduction in CAT. GPx changes were related to the presence of risk factors such as high-risk IPSS-R or mutational score. Moreover, there was an increase in IL-2, IL-6, IL-8, and TNF-α plasma levels, with a further increase of IL-2 and IL-10 from early to advanced stages of the disease. However, we did not observe any association between inflammation and oxidative stress. Finally, 5-azacitidine treatment generated oxidative stress in MDS patients, without affecting inflammation levels, suggesting that oxidative status and inflammation are two independent processes.

Keywords: 5-azacitidine; cytokines; inflammation; myelodysplastic syndrome (MDS); oxidative stress; somatic alterations.

Figure 1

Analysis of erythrocyte and plasmatic oxidative stress parameters in myelodysplastic syndrome (MDS) patients and controls. MDS patients were divided at diagnosis or only with supportive care (untreated MDS) or MDS patients treated with 5-azacitidine (5-AZA MDS). The following oxidative stress levels are represented: (A) erythrocyte levels of oxidized glutathione (GSSG); (B) reduced glutathione (GSH); (C) GSSG·GSH⁻¹ ratio; (D) catalase (CAT) and (E) glutathione peroxidase (GPx) activity; (F) lipid peroxidation (LPO) and (G) advanced oxidation protein products (AOPP) plasma levels. Data are presented as mean ± SEM. ** p < 0.01, *** p < 0.001 vs. control; # p < 0.05 vs. 5-AZA MDS group.

Figure 2

Concentration of pro- and anti-inflammatory cytokines in plasma samples from myelodysplastic syndrome (MDS) patients. (A) IL-2, (B) IL-6, (C) IL-8, (D) IL-10 and (E) TNF-α plasma concentration of MDS patients at diagnosis or with supportive care (untreated MDS) and MDS patients treated with 5-azacitidine (5-AZA MDS). Data are presented as mean ± SEM. ** p < 0.01, *** p < 0.001 vs. control.

Figure 3

Oxidative stress biomarkers during myelodysplastic syndrome (MDS) progression. (A) erythrocyte GSSG·GSH⁻¹ ratio; (B) glutathione peroxidase (GPx) and (C) catalase (CAT) activities; (D) lipid peroxidation (LPO); (E) advanced oxidation protein products (AOPP); (F) nitrite plus nitrate; and (G) CoQ10 levels in plasma in early stage (ES untreated MDS) vs. advanced stage of untreated MDS patients (AS untreated MDS). Data are presented as mean ± SEM. * p < 0.05, ** p < 0.01, *** p < 0.001 vs. control; # p < 0.05 vs. ES untreated MDS group.

Figure 4

Concentration of pro- and anti-inflammatory cytokines during myelodysplastic syndrome (MDS) progression. (A) IL-2, (B) IL-6, (C) IL-8, (D) IL-10 and (E) TNF-α plasma concentration in early stage (ES untreated MDS) vs. advanced stage (AS untreated MDS) from untreated MDS patients. * p < 0.05, ** p < 0.01, *** p < 0.001 vs. control; # p < 0.05 vs. ES untreated MDS group.

Figure 5

Risk prognostic factors and leucocyte populations in MDS patients. GPx activity in untreated MDS patients according to (A) IPSS-R score, (B) mutational score and (C) molecular risk. (D) Leucocyte populations, (E) neutrophils and (F) monocytes in untreated MDS patients and 5-AZA group. # p < 0.05, ## p < 0.01; *** p < 0.001 vs. control.