Tanshinone II A inhibits dendritic cell-mediated adaptive immunity: potential role in anti-atherosclerotic activity / 中国结合医学杂志

<p><b>OBJECTIVE</b>Antigen-presenting cells such as monocytes and dendritic cells (DCs) stimulate T-cell proliferation and activation during adaptive immunity. This cellular interaction plays a role in the growth of atherosclerotic plaques. Tanshinone II A (TSN) had been shown to decrease the growth of atherosclerotic lesions. We therefore investigated the ability of TSN to inhibit human monocyte-derived DCs and their T-cellstimulatory capacity.</p><p><b>METHODS</b>DCs derived from human monocytes cultured with recombinant human interleukin (IL)-4 and recombinant human granulocyte-macrophage colony-stimulating factor were co-cultured with TSN and lipopolysaccharide for 48 h. Phosphate-buffered saline was used as a negative control. Activation markers and the capacity of DCs for endocytosis were measured by flow cytometry, and proinflammatory cytokines were measured by enzyme-linked immunosorbent assays. DCs were co-cultured with lymphocytes to measure T-cell proliferation and IL-2 secretion by mixed lymphocyte reactions.</p><p><b>RESULTS</b>TSN dose-dependently attenuated DC expression of costimulatory molecules (CD86), and decreased expression of major histocompatibility complex class II (human loukocyte antigen-DR) and adhesion molecules (CD54). Moreover, TSN reduced secretion of the proinflammatory cytokines IL-12 and IL-1 by human DCs, and restored the capacity for endocytosis. Finally, TSN-preincubated DCs showed a reduced capacity to stimulate T-cell proliferation and cytokine secretion.</p><p><b>CONCLUSIONS</b>TSN inhibits DC maturation and decreases the expression of proinflammatory cytokines, while impairing their capacity to stimulate T-cell proliferation and cytokine secretion. These effects may contribute to the influence of TSN on the progression of atherosclerotic lesions.</p>

Changes of CD4+CD28- T cell and CD4+CD25+ regulatory T cell subsets in patients with coronary heart disease / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes of CD4(+)CD28(-) T cell and CD4(+)CD25(+) regulatory T cell (Treg) subsets in patients with coronary artery disease (CAD).</p><p><b>METHODS</b>Twenty-eight patients with angiographically established CAD were recruited in this study, including 16 with unstable angina (UA group) and 12 with stable angina (SA group). Eleven patients with chest pain syndrome served as the control group. The proportions of peripheral CD4(+)CD28(-) T cells and CD4(+)CD25(+) Treg subsets were determined with fluorescence-activated cell sorting (FACS).</p><p><b>RESULTS</b>The proportions of CD4(+)CD25(+) Treg were significantly lower in UA group (6.55-/+2.45%) than in SA (14.01-/+4.92%) and control groups (13.55-/+3.87%). The proportions of CD4(+)CD28(-) T cells were significantly higher in UA group (10.55-/+4.76%) than in SA (2.64-/+1.33%) and control (2.75-/+1.55%) groups.</p><p><b>CONCLUSION</b>Alterations of circulating T-lymphocyte subsets occur in patients with UA. The changes of Treg and CD4(+)CD28(-) T cells may lead to breakdown of peripheral autoimmune tolerance and play an important role in the development and progression of CHD.</p>

Effect of urotensin II on secretion of adrenomedullin from human vascular endothelial cells / 中华心血管病杂志

<p><b>OBJECTIVE</b>To study the effect of human urotensin II (HU II) on secretion of adrenomedullin (ADM) from human vascular endothelial cells (HVEC) and its mechanism.</p><p><b>METHODS</b>In cultured HVEC, different concentrations of HUII were used to stimulate the ADM secretion from HVEC, and the inhibitors of different signal transduction pathway were used to investigate their effects on ADM secretion. The contents of ADM in medium were determined by radio immunoassay.</p><p><b>RESULTS</b>HUII stimulated secretion of ADM from HVEC in a time-dependent and concentration-dependent manner. The contents of ADM in the experiment groups were changed compared with that in control group (P < 0.05). The increase of ADM could be inhibited by inhibitor of extracellular signal-regulated protein kinase (PD(98059)), inhibitor of P38 kinase (SB(202190)), inhibitor of calmodulin (W(7)) and inhibitor of Ca(2+) (nicardipine) (P < 0.05). The inhibition ratio in those groups was 68%, 78%, 24% and 25% respectively. But the inhibitor of Calcineurin (CaN) and inhibitor of protein kinase C (H(7)) had no influence on the secretion of ADM from HVEC (P > 0.05).</p><p><b>CONCLUSION</b>The stimulated effect of HUII on the ADM secretion from HVEC may be mediated by Ca(2+), ERKs, CaM-PK and P38 signal transduction pathways.</p>