Chih-Pei Lin

Plasma matrix metalloproteinase-3 level is an independent prognostic factor in stable coronary artery disease

Background  Recent evidence suggests the important role of matrix metalloproteinases (MMPs) in the progression of atherosclerosis and development of clinical events. We assessed the prognostic value of different plasma MMPs in patients with stable coronary artery disease (CAD).

Differential mononuclear cell activity and endothelial inflammation in coronary artery disease and cardiac syndrome X

BACKGROUND Circulating mononuclear cells could be activated with endothelial inflammation in patients with coronary artery disease (CAD). In some patients with normal coronary angiograms, myocardial ischemia could also present with coronary microvascular dysfunction (cardiac syndrome X). This study was undertaken to investigate whether mononuclear cell activation and endothelial inflammation can present in syndrome X patients. METHODS We evaluated the biochemical parameters, circulating soluble adhesion molecules, circulating superoxide free radicals, and mononuclear cell activity in 32 patients with syndrome X, 34 with angiographically documented CAD, and 17 age- and gender-matched healthy control subjects. RESULTS Compared to that in control subjects, plasma high-density lipoprotein was reduced (P<0.001) and insulin to glucose ratio increased (P=0.02) in CAD patients. Circulating level of soluble intracellular adhesion molecule-1 was significantly higher in both syndrome X and CAD patients than in control subjects (P<0.01), whereas the levels of soluble vascular cell adhesion molecule (P=0.02) and von Willebrand factor (P=0.01) were increased in CAD patients only. The peak (P<0.001) and total counts of superoxide free radicals in whole blood (P<0.001) was significantly higher in syndrome X patients than in the other two groups. However, phorbol-12-myristate-13-acetate-induced superoxide free radical generation of mononuclear cells was increased in CAD (10.5+/-4.6%, P=0.01) but not in syndrome X patients (8.7+/-2.0%) as compared with control subjects (7.7+/-0.5%). CONCLUSIONS The results indicated that the activity of mononuclear cells was increased with significant endothelial inflammation and injury in CAD patients. In syndrome X patients, though circulating superoxide free radicals were increased, there was minimal endothelial inflammation without mononuclear cell activation. The relatively preserved lipid and metabolic profiles might contribute to less vascular inflammation in syndrome X patients.

Far infra-red therapy promotes ischemia-induced angiogenesis in diabetic mice and restores high glucose-suppressed endothelial progenitor cell functions

BackgroundFar infra-red (IFR) therapy was shown to exert beneficial effects in cardiovascular system, but effects of IFR on endothelial progenitor cell (EPC) and EPC-related vasculogenesis remain unclear. We hypothesized that IFR radiation can restore blood flow recovery in ischemic hindlimb in diabetic mice by enhancement of EPCs functions and homing process.Materials and methodsStarting at 4 weeks after the onset of diabetes, unilateral hindlimb ischemia was induced in streptozotocine (STZ)-induced diabetic mice, which were divided into control and IFR therapy groups (n = 6 per group). The latter mice were placed in an IFR dry sauna at 34°C for 30 min once per day for 5 weeks.ResultsDoppler perfusion imaging demonstrated that the ischemic limb/normal side blood perfusion ratio in the thermal therapy group was significantly increased beyond that in controls, and significantly greater capillary density was seen in the IFR therapy group. Flow cytometry analysis showed impaired EPCs (Sca-1+/Flk-1+) mobilization after ischemia surgery in diabetic mice with or without IFR therapy (n = 6 per group). However, as compared to those in the control group, bone marrow-derived EPCs differentiated into endothelial cells defined as GFP+/CD31+ double-positive cells were significantly increased in ischemic tissue around the vessels in diabetic mice that received IFR radiation. In in-vitro studies, cultured EPCs treated with IFR radiation markedly augmented high glucose-impaired EPC functions, inhibited high glucose-induced EPC senescence and reduced H2O2 production. Nude mice received human EPCs treated with IFR in high glucose medium showed a significant improvement in blood flow recovery in ischemic limb compared to those without IFR therapy. IFR therapy promoted blood flow recovery and new vessel formation in STZ-induced diabetic mice.ConclusionsAdministration of IFR therapy promoted collateral flow recovery and new vessel formation in STZ-induced diabetic mice, and these beneficial effects may derive from enhancement of EPC functions and homing process.

Deletion of FHL2 Gene Impaired Ischemia-Induced Blood Flow Recovery by Modulating Circulating Proangiogenic Cells

Objective—The four and a half Lin11, Isl-1 and Mec-3 (LIM) domain protein 2 (FHL2) is a member of the four and a half LIM domain-only (FHL) gene family, and has been shown to play an important role in inhibiting inflammatory angiogenesis. Here, we tested the hypothesis that impaired ischemia-induced neovascularization in mice lacking FHL2 is related to a defect in proangiogenic cell mobilization and functions in vasculogenesis. Approach and Results—Unilateral hindlimb ischemia surgery was conducted in FHL2−/− mice and wild-type (FHL2+/+) mice. After hindlimb ischemia surgery, expression of FHL2 protein was noted in ischemic tissues of wild-type mice. All FHL2-null mice (100%) suffered from spontaneous foot amputation, but only 20% of wild-type mice had ischemia-induced foot amputation after ischemic surgery. Blood flow recovery was significantly impaired in FHL2−/− mice when compared with that in wild-type mice as determined by laser Doppler imaging. Histological analysis revealed that the capillary density in the ischemic limb was increased in wild-type mice, whereas no such increase was noted in FHL2−/− mice. Flow cytometry demonstrated that the number of CD34+ or CD34+/Sca-1+/Flk-1+ in peripheral blood after ischemic surgery significantly decreased in FHL2-null mice than those in wild-type mice after hindlimb ischemia surgery. FHL2 deficiency impaired ex vivo angiogenesis in mouse aortic-ring culture assay, which revealed that the mean density of the microvessels was significantly higher in the wild-type aorta than in the FHL2−/− aorta. Western blot analysis showed that vascular endothelial growth factor (VEGF), interleukin-6, matrix metalloproteinase-2, matrix metalloproteinase-9, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1 levels were significantly downregulated in ischemic muscles in FHL2-null mice compared with wild-type mice. Deletion of FHL2 protein by FHL2 small interfering RNA impaired VEGF production under hypoxia conditions, and also suppressed endothelial progenitor cell angiogenic functions, but these effects could be recovered by administration of VEGF. Conclusions—Deficiency of FHL2 impairs ischemia-induced neovascularization, and these suppressive effects may occur through a reduction in proangiogenic cell mobilization, migration, and vasculogenesis functions.

Direct effect of statins on homocysteine-induced endothelial adhesiveness: potential impact to human atherosclerosis

Background  Although homocysteine (HCY) is a risk factor for cardiovascular diseases, recent clinical trials failed to show the benefits by reducing plasma HCY. Alternative strategy with 3‐hydroxy‐3‐methylglutaryl coenzyme A reductase inhibitors, statins, might be feasible. This study investigated HCY‐induced endothelial adhesiveness with mononuclear cells (MNCs) from patients with coronary artery disease (CAD). The direct endothelial protective effects of statins were also examined.

Effects of simvastatin withdrawal on serum matrix metalloproteinases in hypercholesterolaemic patients

Background  Serum matrix metalloproteinase (MMP) levels have been related to clinical outcomes in patients with coronary artery disease. Though statin treatment might reduce serum MMPs the change of levels after statin withdrawal remains obscure.

Zoledronate inhibits ischemia-induced neovascularization by impairing the mobilization and function of endothelial progenitor cells.

Background Bisphosphonates are a class of pharmacologic compounds that are commonly used to treat postmenopausal osteoporosis and malignant osteolytic processes. Studies have shown that bone marrow-derived endothelial progenitor cells (EPCs) play a significant role in postnatal neovascularization. Whether the nitrogen-containing bisphosphonate zoledronate inhibits ischemia-induced neovascularization by modulating EPC functions remains unclear. Methodology/Principal Findings Unilateral hindlimb ischemia was surgically induced in wild-type mice after 2 weeks of treatment with vehicle or zoledronate (low-dose: 30 μg/kg; high-dose: 100 μg/kg). Doppler perfusion imaging demonstrated that the ischemic limb/normal side blood perfusion ratio was significantly lower in wild-type mice treated with low-dose zoledronate and in mice treated with high-dose zoledronate than in controls 4 weeks after ischemic surgery (control vs. low-dose vs. high-dose: 87±7% vs. *61±18% vs. **49±17%, *p<0.01, **p<0.005 compared to control). Capillary densities were also significantly lower in mice treated with low-dose zoledronate and in mice treated with high-dose zoledronate than in control mice. Flow cytometry analysis showed impaired mobilization of EPC-like cells (Sca-1+/Flk-1+) after surgical induction of ischemia in mice treated with zoledronate but normal levels of mobilization in mice treated with vehicle. In addition, ischemic tissue from mice that received zoledronate treatment exhibited significantly lower levels of the active form of MMP-9, lower levels of VEGF, and lower levels of phosphorylated eNOS and phosphorylated Akt than ischemic tissue from mice that received vehicle. Results of the in vitro studies showed that incubation with zoledronate inhibited the viability, migration, and tube-forming capacities of EPC. Conclusions/Significance Zoledronate inhibited ischemia-induced neovascularization by impairing EPC mobilization and angiogenic functions. These findings suggest that administration of zoledronate should be withheld in patients with ischemic events such as acute limb ischemia.

Intraocular pressure-lowering effect of auricular acupressure in patients with glaucoma: a prospective, single-blinded, randomized controlled trial.

OBJECTIVE The objective of the study was to evaluate the effect of auricular acupressure in controlling intraocular pressure (IOP) in patients with glaucoma. DESIGN Thirty-three (33) patients were recruited through advertisement at the clinic for glaucoma. These patients were divided into the auricular acupressure group (16 patients, 28 glaucoma eyes) and the sham group (17 patients, 32 glaucoma eyes). Patients in the acupressure group received auricular acupoint (kidney, liver, and eye) stimulator tapping and regular massage twice a day for 4 weeks. Patients in the sham group received tapping at sham auricular acupoints (wrist, shoulder, and jaw) without massage stimulation. The IOP and visual acuity (VA) were assessed before and after the treatment in the first 4 weeks and followed up, up to 8 weeks. RESULTS After the treatment and at the 8-week follow-up, IOP and VA improved significantly in the acupressure group when compared with pretreatment (p < 0.05). The most significant IOP-lowering effect was seen at about 3-4 weeks after auricular acupressure. IOP returned to the initial level after acupressure had been discontinued for 4 weeks. Significant improvement of the uncorrected VA (UCVA) was noted at about 2-4 weeks in the acupressure group. UCVA improvement was also noted in the sham group. The difference was only significant in week 3. Improvement of the best-corrected VA was noted in both groups, but was only significant in week 2. CONCLUSIONS Our data suggest that auricular acupressure can be used as a complementary treatment to ameliorate IOP and VA for patients with glaucoma.

Anti-inflammatory strategies for homocysteine-related cardiovascular disease.

Homocysteine may induce vascular damage for atherosclerosis. Vitamin/folate supplementation has been proposed to reduce the cardiovascular disease risk. Nevertheless, there is no randomized clinical trial clearly proving the efficacy of reducing the homocysteine as a means of lowering the incidence of cardiovascular disease. Homocysteine induces oxidative stress leading to endothelial dysfunction. In addition, homocysteine-induced oxidative stress favors lipid peroxidation and induces production of inflammatory factors, thus accelerating atherosclerosis. In this paper, we reviewed the available evidence concerning the association between homocysteine and cardiovascular disease, with the objective of discussing the pertinence of screening, treatment, and prevention of hyperhomocysteinemia-related cardiovascular disease. Our previous findings also indicated the significant role of mononuclear cells activation in homocysteine-induced endothelial dysfunction; treatment with statins attenuated homocysteine-induced endothelial adhesiveness, indicating the novel endothelial protection effects of statins in the presence of homocysteine. Since inflammation and oxidative stress are critical to homocysteine-induced vascular damage, the improvement of endothelial dysfunction and the inhibition of mononuclear cell activation by anti-inflammatory and/or antioxidative drugs/agents may serve as the potential therapeutic strategy for hyperhomocysteinemia-related cardiovascular disease.

Simvastatin Attenuates Oxidative Stress, NF-κB Activation, and Artery Calcification in LDLR-/- Mice Fed with High Fat Diet via Down-regulation of Tumor Necrosis Factor-α and TNF Receptor 1

Simvastatin (SIM) is anti-inflammatory. We used low density lipoprotein receptor knockout (LDLR-/-) mice and human aortic smooth muscle cells (HASMCs) as model systems to study the effect of SIM on arterial calcification and to explore the potential mechanisms contributing to this protective effect. High-fat diet (HFD) caused the LRLR -/- to develop dyslipidemia, diabetics, atherosclerosis and aortic smooth muscle calcification. SIM, N-acetyl cysteine (NAC, a ROS scavenger) and apocynin (APO, a NADPH oxidase inhibitor) did not significantly retard the development of dyslipidemia or diabetic. However, those treatments were still effective in attenuating the HFD-induced atherosclerosis and aortic smooth muscle calcification. These findings suggest that the protective effect of SIM against aortic calcification is not contributed by the cholesterol lowering effect. SIM, NAC and APO were found to attenuate the HFD induced elevation of serum TNF-α, soluble TNFR1 (sTNFR1), 3-nitro-tyrosine. We hypothesized that the pro-inflammatory cytokine, oxidative stress and TNFR1 played a role in inducing aortic calcification. We used HASMC to investigate the role of TNF-α, oxidative stress and TNFR1 in inducing aortic calcification and to elucidate the mechanism contributes the protective effect of SIM against aortic calcification. We demonstrated that treating HASMC with TNF-α induced cell Ca deposit and result in an increase in ALP, NADPH oxidase activity, NF-kB subunit p65, BMP2, MSX2, and RUNX2 expression. SIM suppressed the TNF-α induced activation of NADPH oxidase subunit p47, the above-mentioned bone markers and TNFR1 expression. Furthermore, p65, p47 and TNFR1 siRNAs inhibited the TNF-α-mediated stimulation of BMP-2, MSX2, RUNX2 expression. SIM, APO, and NAC either partially inhibit or completely block the TNF-α induced H2O2 or superoxide production. These results suggest that SIM may, independent of its cholesterol-lowering effect, suppresses the progression of vascular diseases through the inhibition of the inflammation mediators TNF-α and TNFR1.