Pseudolaric acid B attenuates atherosclerosis progression and inflammation by suppressing PPARγ-mediated NF-κB activation.

AIMS/OBJECTIVE: Atherosclerosis is a progressive disease of large arteries characterized with chronic inflammation and aberrant immune response. Pseudolaric acid B (PB) has been found to exert multiple effects by inhibiting inflammatory response. However, there is no comprehensive assessment of the effects of PB on atherosclerosis using relevant in vivo and in vitro models. MATERIAL AND METHODS: Male ApoE-/- mice were treated with PB orally with a high fat diet (HFD) to clarify its anti-atherosclerotic activities. RAW264.7 macrophage line, a well-accepted cell model of atherosclerosis, was used to investigate anti-inflammatory effects and molecular mechanisms of PB. RESULTS: PB significantly attenuated atherosclerotic lesions by modulating plasma lipid profiles as well as inhibiting inflammatory responses in macrophages of atherosclerotic mice. Meanwhile, PB markedly suppressed the expression of pro-inflammatory cytokines, and regulated cholesterol efflux related genes in oxidative low density lipoprotein (ox-LDL)-loaded macrophages. The cellular uptake of Dil-labeled ox-LDL was significantly inhibited by PB either. Moreover, the ability of PB to suppress nuclear factor kappa B (NF-κB) and activate peroxisome proliferator-activated receptor gamma (PPARγ) was confirmed using luciferase reporter assays. Conversely, the selective PPARγ antagonist GW9662 reversed the influence of PB in macrophages. CONCLUSION: Together, these findings indicate that PB exerts its protective effects on atherosclerosis by inhibiting macrophage-mediated inflammatory response and cellular ox-LDL uptake, and promoting cholesterol efflux by suppressing NF-κB activation PPARγ-dependently. Therefore, PB may be a promising agent for inflammatory and atherosclerotic diseases.

Discordance Between VASP Phosphorylation and Platelet Aggregation in Defining High On-Clopidogrel Platelet Reactivity After ST-Segment Elevation Myocardial Infarction.

To investigate potential clinical characteristics associated with discordance between platelet vasodilator-stimulated phosphoprotein phosphorylation (VASP-P) flow cytometry (FCM) assay and light transmission aggregometry (LTA) in defining high on-clopidogrel platelet reactivity (HPR) after ST-segment elevation myocardial infarction (STEMI). In this study, platelet responsiveness was measured by the above 2 methods simultaneously on day 1 and on day 6 of STEMI onset in 90 consecutive patients who underwent primary percutaneous coronary intervention. The FCM-derived platelet reactivity index and LTA-derived platelet aggregation rate were both significantly reduced after dual antiplatelet therapy on day 6. Multiple variable-adjusted logistic regression analysis revealed that smoking (odds ratio [OR]: 4.507, 95% confidence interval [CI]: 1.123-18.09, P = .034) and onset-to-admission time (per 1 hour increase, OR: 1.196, 95% CI: 1.023-1.398, P = .025) both were independent predictors for the discordance between the 2 methods. Additionally, improved correlation and concordance was observed in nonsmokers compared with smokers. Our data show that smoking and prolonged onset-to-admission time are associated with discordance between platelet VASP-P and LTA in defining HPR after STEMI, which should be considered when planning personalized antiplatelet therapy.

Th17/Treg Imbalance Induced by Dietary Salt Variation Indicates Inflammation of Target Organs in Humans.

The functions of T helper 17 (Th17) and regulatory T (Treg) cells are tightly orchestrated through independent differentiation pathways that are involved in the secretion of pro- and anti-inflammatory cytokines induced by high-salt dietary. However, the role of imbalanced Th17/Treg ratio implicated in inflammation and target organ damage remains elusive. Here, by flow cytometry analysis, we demonstrated that switching to a high-salt diet resulted in decreased Th17 cells and reciprocally increased Treg cells, leading to a decreased Th17/Treg ratio. Meanwhile, Th17-related pathway was down-regulated after one day of high salt loading, with the increase in high salt loading as shown by microarray and RT-PCR. Subsequently, blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) observed hypoxia in the renal medulla (increased R2(*) signal) during high-salt loading, which was regressed to its baseline level in a step-down fashion during low-salt feeding. The flow-mediated vasodilatation (FMD) of the branchial artery was significantly higher on the first day of high salt loading. Collectively, these observations indicate that a short-term increase in dietary salt intake could induce reciprocal switches in Th17/Treg ratio and related cytokines, which might be the underlying cellular mechanism of high-salt dietary induced end organ inflammation and potential atherosclerotic risk.

The Kinetics of Circulating Monocyte Subsets and Monocyte-Platelet Aggregates in the Acute Phase of ST-Elevation Myocardial Infarction: Associations with 2-Year Cardiovascular Events.

In experimental myocardial infarction (MI), a rise in cell counts of circulating monocyte subsets contributes to impaired myocardial healing and to atherosclerotic plaque destabilization. In humans, the prognostic role of monocyte subsets in patients suffering ST-elevation MI (STEMI) is still unclear. In the present study, we aimed to determine the kinetics of the 3 monocyte subsets (classical CD14++CD16-, intermediate CD14++CD16+, and nonclassical CD14+CD16++ monocytes), as well as the subset-specific monocyte-platelet aggregates (MPA), in acute STEMI followed by primary percutaneous coronary intervention (PCI), and their relationships with cardiovascular outcomes during a 2-year follow-up.Monocyte subsets and MPA were measured in 100 STEMI patients receiving primary PCI on days 1, 2, 3, 5, and 7 of symptom onset, which were compared with 60 stable coronary heart disease patients and 35 healthy volunteers. From day 1 to day 7, significant increases in the counts of CD14++CD16+ monocytes and CD14++CD16+ MPA were observed, with peak levels on day 2. During a median follow-up of 2.0 years, 28 first cardiovascular events (defined as cardiovascular death, nonfatal ischemic stroke, recurrent MI, need for emergency or repeat revascularization, and rehospitalization for heart failure) were recorded. After adjustment for confounders, CD14++CD16+ monocytosis (day 1 [HR: 3.428; 95% CI: 1.597-7.358; P = 0.002], day 2 [HR: 4.835; 95% CI: 1.106-21.13; P = 0.04], day 3 [HR: 2.734; 95% CI: 1.138-6.564; P = 0.02], and day 7 [HR: 2.647; 95% CI: 1.196-5.861; P = 0.02]), as well as increased levels of CD14++CD16+ MPA measured on all time points (days 1, 2, 3, 5, and 7), had predictive values for adverse cardiovascular events.In conclusion, our data show the expansion of the CD14++CD16+ monocyte subset during acute phase of STEMI has predictive values for 2-year adverse cardiovascular outcomes in patients treated with primary PCI. Future studies will be warranted to elucidate whether CD14++CD16+ monocytes may become a target cell population for new therapeutic strategies after STEMI.

Temporal and spatial characterization of mononuclear phagocytes in circulating, lung alveolar and interstitial compartments in a mouse model of bleomycin-induced pulmonary injury.

The mononuclear phagocyte system, including circulating monocytes and tissue resident macrophages, plays an important role in acute lung injury and fibrosis. The detailed dynamic changes of mononuclear phagocytes in the circulating, lung alveolar and interstitial compartments in bleomycin-induced pulmonary injury model have not been fully characterized. The present study was designed to address this issue and analyzed their relationships with pulmonary pathological evolution after bleomycin challenge. A total of 100 male C57BL/6 mice were randomly divided to receive bleomycin (2.5mg/kg, n=50) or normal saline (n=50) via oropharyngeal approach, and were sacrificed on days 1, 3, 7, 14 and 21. Circulating monocyte subsets, polarization state of bronchoalveolar lavage fluid (BALF)-derived alveolar macrophages (AMφ) and lung interstitial macrophages (IMφ, derived from enzymatically digested lung tissue) were analyzed by flow cytometry. There was a rapid expansion of circulating Ly6C(hi) monocytes which peaked on day 3, and its magnitude was positively associated with pulmonary inflammatory response. Moreover, an expansion of M2-like AMφ (F4/80+CD11c+CD206+) peaked on day 14, and was positively correlated with the magnitude of lung fibrosis. The polarization state of IMφ remained relatively stable in the early- and mid-stage after bleomycin challenge, expect for an increase of M2-like (F4/80+CD11c-CD206+) IMφ on day 21. These results support the notion that there is a Ly6C(hi)-monocyte-directed pulmonary AMφ alternative activation. Our result provides a dynamic view of mononuclear phagocyte change in three compartments after bleomycin challenge, which is relevant for designing new treatment strategies targeting mononuclear phagocytes in this model.

Changes in morphology and activity of transglutaminase following cross-linking and immobilization on a polypropylene microporous membrane.

Transglutaminase (TGase) was cross-linked with glutaraldehyde, and cross-linked crystalline transglutaminase was immobilized on a polypropylene microporous membrane by UV-induced grafting. Immobilized enzyme activity were calculated to be 0.128 U/cm² polypropylene microporous membrane. The microstructure and enzyme characteristics of free, cross-linked and immobilized transglutaminase were compared. The optimum temperature of free transglutaminase was determined to be approximately 40 °C, while cross-linking and immobilization resulted in an increase to approximately 45 °C and 50 °C. At 60 °C, immobilized, cross-linked and free transglutaminase retained 91.7 ± 1.20%, 63.2 ± 1.05% and 37.9 ± 0.98% maximum activity, respectively. The optimum pH was unaffected by the state of transglutaminase. However, the thermal and pH stabilities of cross-linked and immobilized transglutaminase were shown to increase.

CT-guided percutaneous radiofrequency ablation of spinal osteoid osteoma.

BACKGROUND: This study evaluated the feasibility, efficacy and safety of CT-guided percutaneous radiofrequency ablation in patients with spinal osteoid osteoma. METHODS: Two patients suffered spinal osteoid osteoma were treated with CT-guided percutaneous radiofrequency ablation under local anesthesia. Lesions located in sacral vertebrae and cervical vertebrae, which were adjacent to nerve root and spinal canal respectively. Tumors were treated under 90°C radiofrequency temperature lasting 4 minutes by an electrode placement. Visual analog scale was used to evaluate the pain improvement. RESULTS: No complications were observed pre- and post-operation. Patients recovered to normal activities immediately and achieved complete pain relief in 24 hours. No symptoms were recurrent in 5 months and 4 months follow up. Mild scoliosis has been recovered in case 2. CONCLUSIONS: CT-guided percutaneous radiofrequency ablation of spinal osteoid osteoma is safe, effective and has more clinical benefits. The long-term outcome needs further observation.