Inhibitory effect of tanshinone on the activation of peripheral blood mononuclear cells in patients with essential hypertension / 中国组织工程研究

ABSTRACT

BACKGROUND: Preactivation of peripheral blood mononuclear cells (PBMCS) is one of the most important eerly events and facilitating factor for the formation of atherosclerosis. Tanshinone is a lipolytic component extracted from traditional Chinese medicine of denshen, it has definite anti-atherosclerotic effect.OBJECTTVE To analyze whether PBMCS preactivation existed at early essential hypertension, and investigate the effects of tanshinone on inhibiting the PBMCS activation cultured in vitro by detecting the adhesion and excretory activities of PBMCS.DESTGN A case-controlled analysis.SETTING: Department of Emergency and Research Room of Traditional Chinese Medicine, Tongji Hospital affiliated to Tongji Medical College, Huazhong University of Science and Technology.PARTTCTPANTS Thirty patients with untreated essential hypertension or with withdrawal from antihypertensives for at least 2 weeks were selected from the Department of Cardiology, Tongji Hospital affiliated to Tongji Medical College,Huazhong University of Science and Technology from January 2003 to October 2004, including 16 males and 14 females, aged (44.6±7.4) years, body mass index of (26.2±4.5) kg/m2, average disease course of (38.5±16.9) months.Informed contents were obtained from all the subjects. Their hypertension was grade Ⅰ-Ⅱ according to the diagnostic standards for hypertension by WHO/ISH in 1999. Secondary hypertension, organic heart disease, hyperglyceridemia,diabetes mellitus, liver and kidney dysfunction, heart, brain, kidney, vessel and other target damaged induced by infection and other clinical conditions and hypertension were excluded by history, physical examination and assistant examination.Another 30 healthy physical examinees with normal blood pressure were enrolled as the normal control group. Human umbilical vein endothelial cells (Species Reserving Center of Wuhan University); Tanshinone injection (Yaan Sanjiu Pharmaceutical, Co., Ltd., batch number 020724);METHODS: ① Venous blood samples (4.0-5.0 mL) were drawn from all the subjects, and mononuclear cells were separated by means of Ficoll-Hypaque density gradient centrifugation and plastic adhesion, then incubated at 37 ℃ for 40-60 minutes, and the adherent cells were the PBMCS. These cells (viability ＞ 95%, Trypan blue staining) had the characteristics of mononuclear cells (Wright staining). The newly separated adherent PBMCS were resuspended, and then inoculated to the 24-well plate (4×107 L-1). There were 3 wells for each sample the first was for basic excretion, the second for angiotensin Ⅱ stimulation, and the third for tanshinone pretreatment. The PBMCS were co-incubated with tanshinone for 30 minutes before angiotensin Ⅱ stimulation. The terminal concentration was 1×10-8 mol/L and 1×10-8 g/L for angiotensin Ⅱ andtanshinone respectively, and that of PBMCS was 2×107 L-1. The cells were cultured in the incubator (CO2 of 0.05 in volume fraction) at 37 ℃ for 24 hours, then the supernatant and cell ingredients were collected respectively. ② The PBMCS suspension was preparedl, and the cellular density was adjusted to 2.5×109 L-1. The human umbilical vein endothelial cells were cultured on the 24-well plate with M199 medium containing fetal bovine serum (0.1 in volume fraction), and spread to monolayer after the cells entered the logarithm phase. Each well was added with PBMCS suspension (100 μL), incubated at 37 ℃ for 2 and 4 hours respectively. The unadherent cells were removed, and the adherent ones were counted after fixed with 20 g/L glutaral, 40 visual sights were counted for each well under high power microscope, and the average value was used. ③ The double-antibody sandwich enzyme-linked immunoabsorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR) were used to determine the concentrations of tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) in supernatant of PBMCS, and the expressions of their mRNA.MATN OUTCOME MEASURES: ① Changes of PBMCS adhesion activity; ② Concentrations of cytokines and their mRNA expressions in supernatant of PBMCS.RESULTS: ① At 2 and 4 hours of inoculation, the numbers of PBMCS adhered to endothelial cells under basic conditions were similar between the hypertension group and normal control group (t =1.153-1.577, P ＞ 0.05); After angiotensin Ⅱ stimulation, the adherent cells were obviously more in the hypertension group than in the normal control group (t =3.842-4.536, P ＜ 0.01); The numbers of the adherent cells were decreased to the same levels after tanshinone pretreatment (t =0.855-1.702, P ＞ 0.05). ②Under basic state, the concentrations of TNF-α, IL-1β and IL-6 in supernatant were all lower in both groups (t =0.981-1.829, P ＞ 0.05); The concentrations of the cytokines after angiotensin Ⅱ stimulation were obviously higher in the hypertension group than in the normal control group (t = 2.442, 5.075, P ＜ 0.01,0.01, 0.05); The concentrations of the cytokines after tanshinone pretreatment were all decreased to different extent, and there were no significant differences (t =1.227-1.940, P ＞ 0.05). Similar changes were observed in the mRNA expressions of the cytokines in PBMCS in the two groups.CONCLUSTON ① The number of PBMCS adhered to endothelial cells, the concentrations and mRNA expressions of the cytokines under basic state in patients with essential hypertension were at the levels of normal subjects, and they were significantly increased after angiotensin Ⅱ stimulation, suggesting that the PBMCS were at preactivation at early essential hypertension. ② Tanshinone could decrease the adhesion and excretory activities of PBMCS in patients with essential hypertension to the normal levels, it is proved that tanshinone can inhibit the further activation of the preactivated PBMCS, and can prevent the occurrence of atherosclerosis to some extent.