Cytokine reducing effect of azelnidipine in human peripheral blood mononuclear cells.

Numerous clinical trials have shown that calcium channel blocker (CCB) therapy improves the clinical outcome in patients with cardiovascular diseases. Since the progression of several types of cardiovascular diseases is closely associated with inflammation, alleviation of inflammation may be one potential mechanism of those beneficial effects of CCB therapy. We examined whether a new CCB (azelnidipine) could influence the inflammatory response of human peripheral blood mononuclear cells (PBMCs), which are recruited to inflammatory lesions and modulate inflammation. We investigated whether azelnidipine affected intracellular signaling and cytokine production by phytohemagglutinin (PHA)-stimulated human PBMCs in vitro. PBMCs were obtained from 10 healthy volunteers and stimulated with PHA. Then relative intracellular calcium ion concentration ([Ca(2+)](i)) was assessed by fluorescence microscopy, and the production of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-alpha (TNF-alpha) were measured by enzyme-linked immunosorbent assay. Stimulation with PHA significantly raised [Ca(2+)](i) and enhanced the production of MCP-1 and TNF-alpha by human PBMCs. Azelnidipine significantly diminished the PHA-induced rise of [Ca(2+)](i), and the production of MCP-1 and TNF-alpha. These findings indicate that azelnidipine might have an anti-inflammatory influence on human PBMCs, although the mechanisms and the difference from other CCBs still remain unclear and further exploration should be required.

Aldosterone synthesis and cytokine production in human peripheral blood mononuclear cells.

Previously, we reported that spironolactone reduced cytokine production in cultured human peripheral blood mononuclear cells (PBMCs) with angiotensin (Ang) II stimulation. To address the mechanisms underlying this effect, we examined the contribution of aldosterone to cytokine production in cultured human PBMCs with Ang II stimulation. PBMCs expressed the messenger RNA (mRNA) of Ang II type 1 receptor (AT1R) and mineralocorticoid receptor (MR) both spontaneously and after Ang II stimulation, but expressed Ang II type 2 receptor (AT2R) under neither condition. After 24 h of incubation, exogenous Ang II induced the expression of CYP11B2 (a key enzyme of aldosterone synthesis) mRNA and caused aldosterone synthesis. CV-11974 (an AT1R antagonist) reduced Ang II-induced aldosterone synthesis, whereas PD-123319 (an AT2R antagonist) had no effect. The concentration of aldosterone peaked earlier than those of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-alpha (TNF-alpha). After 48 h of incubation (under the influence of synthesized aldosterone), CV-11974 and spironolactone significantly reduced the Ang II-enhanced production of MCP-1 and TNF-alpha, whereas PD-123319 also had no effect. In conclusion, Ang II induces aldosterone synthesis through AT1R and enhances cytokine production through an AT1R-dependent mechanism and, at least partly, through a MR-dependent mechanism in human PBMCs.

Anti-inflammatory effect of spironolactone on human peripheral blood mononuclear cells.

We evaluated the effect of alacepril, CV-11974, and spironolactone on the production of monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-alpha (TNF-alpha) in cultured human peripheral blood mononuclear cells stimulated with angiotensin (Ang) II. Alacepril, CV-11974, and spironolactone significantly reduced the enhanced production of MCP-1 and TNF-alpha induced by exogenous Ang II. Specifically, 10 muM of spironolactone significantly reduced cytokine production, compared to the same dose of alacepril or CV-11974. These findings indicate that spironolactone may contribute to ameliorate the prognosis of patients with cardiovascular diseases by reducing Ang II-induced inflammation, although further exploration including determining the mechanisms would be required.