Differential effect of telmisartan and amlodipine on monocyte chemoattractant protein-1 and peroxisome proliferator-activated receptor-gamma gene expression in peripheral monocytes in patients with essential hypertension

Abstract

Monocyte chemoattractant protein-1 (MCP-1) and peroxisome proliferator-activated receptor-γ (PPAR-γ) play a significant role in monocyte activation, vascular inflammation, and atherogenesis. Angiotensin receptor blockers and calcium channel blockers are antihypertensive drugs with established efficacy and a favorable safety profile. We investigated the effect of telmisartan--an angiotensin receptor blocker with PPAR-γ agonist activity--and amlodipine on the activation state of peripheral blood monocytes with respect to MCP-1 and PPAR-γ gene expression in hypertensives. We recruited 31 previously untreated patients with essential hypertension who were randomly assigned to receive treatment with telmisartan (n = 16) or amlodipine (n = 15). Blood samples were taken before and 3 months after therapy initiation. Mononuclear cells were isolated and mRNAs of MCP-1 and PPAR-γ were estimated by real-time quantitative reverse transcription-polymerase chain reaction each time. The 2 treatments decreased all blood pressure components significantly (p <0.001). In contrast, in the amlodipine group, MCP-1 gene expression was significantly downregulated after treatment with telmisartan (from 21.4 ± 20.5 to 8.1 ± 6.5, p = 0.009), whereas the amlodipine group did not show any significant change (12.5 ± 8.5 vs 17.6 ± 16.4, p = NS). In addition, PPAR-γ mRNA levels showed a significant increase in telmisartan-treated patients (from 20 ± 18.5 to 42.6 ± 36, p = 0.006) and no significant alterations in the amlodipine group (from 29.6 ± 42.5 to 24.2 ± 27.7, p = NS). In conclusion, treatment with telmisartan results in a significant attenuation of MCP-1 gene expression and an increase of PPAR-γ gene expression in peripheral monocytes in patients with essential hypertension. Our findings may provide new insights into the cardiovascular protection of telmisartan in hypertensives.