Ying-Jun Ding

The Th17/Treg imbalance in patients with acute coronary syndrome.

Atherosclerosis is a chronic inflammatory disease regulated by T lymphocyte subsets. Recently, CD4+CD25+Foxp3+ regulatory T (Treg) cells and Th17 cells have been described as two distinct subsets from Th1 and Th2 cells and have the opposite effects on autoimmunity. Th17/Treg balance controls inflammation and may be important in the pathogenesis of plaque destabilization and the onset of acute coronary syndrome [ACS, including unstable angina (UA) and acute myocardial infarction (AMI)]. To assess whether this balance was broken in patients with coronary heart disease, we detected Th17/Treg functions on different levels including cell frequencies, related cytokine secretion and key transcription factors in patients with AMI, UA, stable angina (SA) and controls. The results demonstrated that patients with ACS revealed significant increase in peripheral Th17 number, Th17 related cytokines (IL-17, IL-6 and IL-23) and transcription factor (RORgammat) levels and obvious decrease in Treg number, Treg related cytokines (IL-10 and TGF-beta1) and transcription factor (Foxp3) levels as compared with patients with SA and controls. Results indicate that Th17/Treg functional imbalance exists in patients with ACS, suggesting a potential role for Th17/Treg imbalance in plaque destabilization and the onset of ACS.

Atorvastatin upregulates regulatory T cells and reduces clinical disease activity in patients with rheumatoid arthritis.

In this study, we investigated the hypothesis that regulatory T cells (Treg) are involved in the immunomodulatory effects of statins on rheumatoid arthritis (RA) patients. The 12-week study cohort consisted of 55 RA patients and 42 control subjects allocated to either a group treated with atorvastatin (AT) (20 mg/day) or a non-AT group. Treg numbers, suppressive function, serum inflammatory markers, and disease activity were evaluated before and after the therapy. Furthermore, the effects of AT on the frequency and suppressive function of Treg were determined in vitro. Our data revealed that the suppressive function of Treg from RA patients significantly decreased compared with that of control subjects. AT significantly reduced erythrosedimentation, C-reactive protein, and disease activity. Concomitantly, Treg numbers and suppressive functions were significantly improved by AT. Consistent with the in vivo experiments, AT promoted the generation of Treg from primary T cells and enhanced preexisting Treg function in vitro. Moreover, we showed that PI3K-Akt-mTOR and ERK signal pathways were involved in the induction of Treg by AT. In conclusion, AT significantly increased Treg numbers and restored their suppressive function in the RA patients, and this may be relevant in the modulation of uncontrolled inflammation in this disorder.

Defective Circulating CD4+CD25+Foxp3+CD127low Regulatory T-cells in Patients with Chronic Heart Failure

Aims: Increasing evidences confirm the role of immune activation in the pathogenesis of chronic heart failure (CHF). Regulatory T cells appear central to the control of immune homeostasis. We assessed the hypothesis that the circulating frequency and function of CD4+CD25+ Foxp3+CD127low T regulatory cells (Tregs) would be deranged in patients with CHF. Methods: Ninety-nine CHF patients due to non-ischemic (NIHF) or ischemic etiology (IHF) and 24 control donors were enrolled in the study. Frequency of circulating Tregs was evaluated by flow cytometry. Foxp3 in peripheral blood mononuclear cells (PBMCs) was assayed at the mRNA level by real-time PCR. Functional properties of Tregs to suppress proliferation and pro-inflammatory cytokines secretion of activated CD4+CD25- T cells were measured by proliferation assay and ELISA. Results: The results demonstrated that CHF patients had significantly lower frequency of circulating Tregs and reduced Foxp3 expression in PBMCs compared with control donors. Moreover, Tregs from CHF patients showed compromised function to suppress CD4+CD25- T cells proliferation and pro-inflammatory cytokines secretion. A similar pattern with reduced Tregs frequency and compromised function was found in both NIHF and IHF patients. Correlation analysis suggested that Tregs frequency and function positively correlated with LVEF, whereas negatively correlated with LVEDD and NT-proBNP in patients with CHF. Conclusions: Our data are the first to demonstrate that frequencies of circulating Tregs in patients with CHF are reduced and their suppressive function compromised independently of the etiology. Defective Tregs may be an underlying mechanism of immune activation in CHF patients.

Atorvastatin Modulates Th1/Th2 Response in Patients With Chronic Heart Failure

BACKGROUND The T-helper (Th)1/Th2 imbalance has been demonstrated to be involved in chronic heart failure (CHF). We sought to determine whether atorvastatin exhibited any effect on CHF through modulating the Th1/Th2 response. METHODS AND RESULTS We measured serum concentrations of interleukin (IL)-12, -18, interferon (IFN)-gamma, IL-4, and IL-10 from 20 controls and 72 patients with nonischemic CHF by enzyme-linked immunosorbent assay. To investigate the effect of atorvastatin in vivo, CHF patients were either classified into a usual therapy group (n = 35) or usual therapy plus atorvastatin (10 mg/day) group (n = 37). Patient serum levels of IFN-gamma and IL-4 were measured at time of admission and 2 weeks after treatment. Peripheral blood mononuclear cells from patients of CHF group were cultured in the presence or absence of atorvastatin (0, 0.4, 1, and 4 micromol/L) in vitro, and IFN-gamma and IL-4 levels were detected. Serum levels of IL-12, IL-18, and IFN-gamma were significantly higher in the CHF group than in the control group. The levels of IFN-gamma and the ratios of IFN-gamma:IL-4 were significantly decreased with atorvastatin treatment both in vivo and in vitro, whereas levels of IL-4 did not differ significantly. CONCLUSIONS Th1 polarization exists in patients with CHF, and atorvastatin can modulate the Th1/Th2 response through inhibiting Th1 cytokine production.

Molecular mechanisms of felodipine suppressing atherosclerosis in high-cholesterol-diet apolipoprotein E-knockout mice.

Oxidative stress and inflammation processes are key components of atherosclerosis, from fatty streak formation to plaque rupture and thrombosis. Evidence has revealed that calcium-channel blockers (CCB) could retard atherogenesis, but the exact mechanisms have not been fully elucidated. The present study was undertaken to investigate the potential effects and molecular mechanisms of the CCB felodipine on the process of atherosclerosis in high-cholesterol-diet (HCD) apolipoprotein E-knockout (ApoE KO) mice. Adult male ApoE KO mice were given a normal diet (ND) or HCD and were randomized to no treatment or felodipine (5 mg / kg per day for 12 weeks). The ApoE KO mice with HCD were associated with a marked increase in plasma lipid levels, atherosclerotic lesion area, and the expressions of NADPH oxidase subunits (p47phox and Rac-1), nuclear factor-κB (NF-κB) in nucleus, phosphor-inhibitors of κB (p-IκB), tumor necrosis-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and vascular cell-adhesion molecule-1 (VCAM-1). These changes were suppressed in mice that were treated with felodipine (5 mg/kg per day for 12 weeks) concomitant with HCD administration, with no significant change in systolic blood pressure and plasma lipid levels. The results suggest that felodipine can attenuate atherosclerosis, and this effect is partly related to inhibition of oxidative stress and inflammatory signal-transduction pathways, which lead to decreases in the expression of inflammatory cytokines.

Molecular mechanisms of irbesartan suppressing atherosclerosis in high cholesterol-diet apolipoprotein E knock-out mice.

OBJECTIVE Atherosclerosis is a chronic inflammatory disease in which the renin-angiotensin-aldosterone system plays an important role. Evidence indicate that the angiotensin type 1 receptor blockers can suppress atherogenesis, but the exact mechanisms have not been fully elucidated. The study was undertaken to investigate the potential effects and molecular mechanisms of an angiotensin type 1 receptor blocker irbesartan on atherogenesis in high cholesterol-diet apolipoprotein E knock-out mice. METHODS AND RESULTS Adult male apolipoprotein E knock-out mice were given normal diet or high cholesterol-diet and randomized to receive no treatment or irbesartan 10 mg kg(-1) d(-1) for 12 weeks. The apolipoprotein E knock-out mice with high cholesterol-diet were associated with a marked increase in atherosclerotic lesion area, plasma lipid and angiotensin II levels, as well as the expressions of angiotensin type 1 receptor in the aorta. High cholesterol-diet feeding increases the activity of NADPH oxidase subunits (p47(phox) and Rac), extracellular signal-regulated kinase 1/2, janus kinase 2, signal transducer and activator of transcription 3, nuclear factor-kappaB and the expression of tumor necrosis factor-alpha, interleukin 6, monocyte chemoattactant protein-1 and vascular cell adhesion molecule-1 in the aortas. These changes were suppressed in mice that were treated with irbesartan 10 mg kg(-1) d(-1), with no significant change in systolic blood pressure and plasma lipid levels. CONCLUSIONS The results suggest that irbesartan can attenuate atherosclerosis, and this effect is partly related to the inhibition of oxidative stress and inflammatory signal transduction pathways which eventually leads to the decrease in the expression of inflammatory cytokines.

Improved Cardiac Performance by Rosuvastatin Is Associated With Attenuations in Both Myocardial Tumor Necrosis Factor-α and p38 MAP Kinase Activity in Rats After Myocardial Infarction

Introduction:Statins have been shown to exert anti-inflammatory effects. The aim of this study was to investigate whether rosuvastatin has favorable effect on ventricular remodeling after myocardial infarction (MI), whether this effect is associated with tumor necrosis factor (TNF)-&agr; expression and p38 mitogen-activated protein (MAP) kinase pathway and, furthermore, whether there is close correlation between gene expression of TNF-&agr; and activity of p38 MAP kinase. Methods and Results:Adult male Wistar rats with acute MI were randomly divided into 2 groups: (1) rosuvastatin-treated group (MI-R) receiving rosuvastatin 20 mg/kg once daily, and (2) infarcted group (MI) receiving saline, when compared with sham-operated control group. Four weeks later, echocardiography, hemodynamics and Van Gieson staining were applied to evaluate left ventricular remodeling and cardiac function. Myocardial gene expression of TNF-&agr; and activity of p38 MAP kinase were analyzed by real time-polymerase chain reaction and Western blot, respectively. The results demonstrated that increased TNF-&agr; gene expression in noninfarcted areas was accompanied by activation of p38 MAP kinase pathway. Moreover, treatment of rosuvastatin markedly improved ventricular remodeling and cardiac function in rats, which was associated with attenuations in both TNF-&agr; gene expression and p38 MAP kinase activity in myocardium without changes in serum lipid levels. Conclusions:Treatment of rosuvastatin was able to improve cardiac remodeling and cardiac function after acute MI, which was associated with attenuations in both expression of TNF-&agr; and activity of p38 MAP kinase in myocardium.

Circulating Th17 cells are not elevated in patients with chronic heart failure.

Abstract Background. Increasing evidences have been obtained that immune activation and inflammation play critical roles in the pathogenesis of chronic heart failure (CHF). T helper (Th) 17 cells are a newly found pro-inflammatory T cell subtype. We therefore assessed the hypothesis that circulating Th17 cells increased in patients with CHF. Hypothesis. Th17 cells and its cytokine might be elevated in patients with CHF. Methods. A total of 92 patients with CHF and 59 healthy donors were enrolled in the study. The frequencies of circulating Th17 cells were determined by flow cytometry. The interleukin (IL)-17 protein levels in the serum and supernatant of phytohemagglutinin (PHA)-stimulated periphery blood mononuclear cells (PBMCs) were detected using ELISA and the mRNA expression of retinoic acid-related orphan receptor (ROR)γt, which is the key transcription factor of Th17 cells was measured by RT-PCR. Results. There were no significant differences in the frequency of circulating Th17 cells, serum level of IL-17, and expression of RORγt in PBMCs between CHF patients and healthy controls. IL-17 protein level in the supernatants of PHA-stimulated PBMCs was also comparable between CHF patients and health donors. Conclusions. Circulating Th17 cells are not elevated in patients with CHF.

Rapamycin modulates the maturation of rat bone marrow-derived dendritic cells

The purpose of the study was to observe the effect of rapamycin (RAPA) on the differentiation and maturation of rat bone marrow-derived dendritic cells (BMDCs) in vitro. BMDCs from Wistar rats were cultured with granulocyte-macrophage colony-stimulating factor plus interleukin-4 in the presence or absence of RAPA (20 ng/mL), and stimulated with lipopolysaccharide (LPS) for 24 h before cells and supernatants were collected. Surface phenotype of BMDCs was flow-cytometrically detected to determine the expression of maturation markers, MHC class II and CD86. Supernatants were analyzed for the production of IL-12 and IFN-γ cytokines by using ELISA. BMDCs were co-cultured with T cells from Lewis rats and mixed lymphocyte reaction was assessed by MTT method. The morphology of BMDCs stimulated with LPS remained immature after RAPA pretreatment. RAPA significantly decreased the CD86 expression, impaired the IL-12 and IFN-γ production of BMDCs stimulated with LPS, and inhibited the proliferation of allogeneic T cells. In conclusion, RAPA can inhibit the maturation of BMDCs stimulated with LPS in terms of the morphology, surface phenotype, cytokine production, and ability of BMDCs to stimulate the proliferation of allogeneic T cells in vitro.SummaryThe purpose of the study was to observe the effect of rapamycin (RAPA) on the differentiation and maturation of rat bone marrow-derived dendritic cells (BMDCs) in vitro. BMDCs from Wistar rats were cultured with granulocyte-macrophage colony-stimulating factor plus interleukin-4 in the presence or absence of RAPA (20 ng/mL), and stimulated with lipopolysaccharide (LPS) for 24 h before cells and supernatants were collected. Surface phenotype of BMDCs was flow-cytometrically detected to determine the expression of maturation markers, MHC class II and CD86. Supernatants were analyzed for the production of IL-12 and IFN-γ cytokines by using ELISA. BMDCs were co-cultured with T cells from Lewis rats and mixed lymphocyte reaction was assessed by MTT method. The morphology of BMDCs stimulated with LPS remained immature after RAPA pretreatment. RAPA significantly decreased the CD86 expression, impaired the IL-12 and IFN-γ production of BMDCs stimulated with LPS, and inhibited the proliferation of allogeneic T cells. In conclusion, RAPA can inhibit the maturation of BMDCs stimulated with LPS in terms of the morphology, surface phenotype, cytokine production, and ability of BMDCs to stimulate the proliferation of allogeneic T cells in vitro.