Migrating Platelets Are Mechano-scavengers that Collect and Bundle Bacteria.

Blood platelets are critical for hemostasis and thrombosis and play diverse roles during immune responses. Despite these versatile tasks in mammalian biology, their skills on a cellular level are deemed limited, mainly consisting in rolling, adhesion, and aggregate formation. Here, we identify an unappreciated asset of platelets and show that adherent platelets use adhesion receptors to mechanically probe the adhesive substrate in their local microenvironment. When actomyosin-dependent traction forces overcome substrate resistance, platelets migrate and pile up the adhesive substrate together with any bound particulate material. They use this ability to act as cellular scavengers, scanning the vascular surface for potential invaders and collecting deposited bacteria. Microbe collection by migrating platelets boosts the activity of professional phagocytes, exacerbating inflammatory tissue injury in sepsis. This assigns platelets a central role in innate immune responses and identifies them as potential targets to dampen inflammatory tissue damage in clinical scenarios of severe systemic infection.

Effects and mechanism of puerarin on the human retinoblastoma cells.

Puerarin is an isoflavonoid that is extracted from Kudzu root and is considered to have an anti-tumor effect. In the present study, the effects of puerarin on human retinoblastoma (RB) cells and the related pathways was determined. The retinoblastoma RB cell lines were used in this study. Cell viability and colony formation capacity were measured by MTT and colony formation assays. Cell cycle was determined by flow cytometry. Cell migration and invasion were examined by Transwell assay. The expression of cell cycle, EMT, and MAPK/ERK signal pathway-related proteins were detected by western blot following puerarin treatment. The results revealed that cell viability and proliferation of RB cells treated with puerarin were significantly lower in RB cells compared to the control group. Puerarin significantly decreased the proportion of cells during S phase which was accompanied with increase in cells at G0/1 and G2 phases. Moreover, puerarin suppressed cell migration, invasion and up-regulated E-Cadherin expression as well as down-regulated Vimentin and α-SMA expression. Furthermore, puerarin treatment suppressed the expression of p-MEK and p-ERK in RB cells. Our findings suggest that puerarin contributes to in the treatment of RB and other malignant tumors.

Ginsenoside Rg1 protects cardiomyocytes from hypoxia-induced injury through the PI3K/AKT/mTOR pathway.

AIM: Myocardial ischemia (MI) is a leading cause of morbidity and mortality which makes the prevention and control of MI tremendously important. We aimed to explore the functional roles of ginsenoside (Gin) Rg1 in cardiomyocytes under hypoxia and to clarify underlying mechanisms. MAIN METHODS: Hypoxia-induced H9c2 cell injury was evaluated by alterations of cell viability, apoptosis and autophagy. Then, effects of Gin Rg1 on hypoxia-induced cell injury were measured. The activation of the phosphatidylinositol-3-kinase (PI3K)/AKT/mechanistic target of rapamycin (mTOR) pathways as well as expression of hypoxia-inducible factor 1α (HIF-1α) was determined with or without addition of PI3K or mTOR inhibitor. Finally, the effects of Gin Rg1 on rat ischemia/reperfusion (I/R) injury and underlying mechanism were studied. KEY FINDINGS: First of all, hypoxia was identified to induce a decrease in cell viability and to increase cell apoptosis and autophagy. Then, these hypoxia-induced alterations were ameliorated by Gin Rg1, which had no effect on cell viability under normoxia. Subsequently, the phosphorylated levels of key kinases in the PI3K/AKT/mTOR pathways as well as expression of HIF-1α were all elevated by Gin Rg1. Activation of the PI3K/AKT/mTOR pathways and HIF-1α expression were inhibited by PI3K inhibitor, and activation of mTOR pathway and HIF-1α expression were inhibited by mTOR inhibitor. More in vivo experiments proved that Gin Rg1 ameliorated rat I/R injury through activating the PI3K/AKT/mTOR pathways. SIGNIFICANCE: Gin Rg1 protected cardiomyocytes from hypoxia-induced cell injury by upregulating HIF-1α through activation of the PI3K/AKT/mTOR pathways.

LncRNA NOP14-AS1 Promotes Tongue Squamous Cell Carcinoma Progression by Targeting MicroRNA-665/HMGB3 Axis.

PURPOSE: The expression profile, clinical effects, and detailed roles of NOP14 antisense RNA 1 (NOP14-AS1) in tongue squamous cell carcinoma (TSCC) remain ambiguous and need to be further explored. Thus, this work was initiated to offer further solid evidence regarding the expression and roles of NOP14-AS1 in TSCC. Furthermore, additional efforts were exerted to reveal the molecular events by which NOP14-AS1 affects the malignant behaviours of TSCC. METHODS: NOP14-AS1 expression was detected in TSCC tissues and cell lines using quantitative reverse transcription-polymerase chain reaction. Cell Counting Kit-8 assay, flow cytometric analysis, Transwell migration and invasion assays, and xenograft tumor model analysis were performed to assess the malignant biological behaviors of TSCC cells after NOP14-AS1 depletion. Mechanistic studies were performed using bioinformatics analysis, luciferase reporter assay, RNA immunoprecipitation, and rescue experiments. RESULTS: NOP14-AS1 upregulation was identified in TSCC tissues and cell lines. Patients with TSCC exhibiting a high NOP14-AS1 expression faced shorter overall survival than those with a low NOP14-AS1 expression. Functionally, NOP14-AS1 depletion facilitated apoptosis and impeded cell proliferation, migration, and invasion in TSCC. In vivo, the growth of TSCC cells was hindered by NOP14-AS1 depletion. Mechanically, NOP14-AS1 functioned as a competing endogenous RNA by sponging microRNA-665 (miR-665), thereby overexpressing the target high mobility group box 3 (HMGB3) of miR-665. Lastly, rescue experiments confirmed that the introduction of HMGB3 overexpression plasmid or miR-665 inhibitor could abrogate the inhibition of aggressive phenotypes triggered by NOP14-AS1 knockdown. CONCLUSION: NOP14-AS1 executed pro-oncogenic activities in TSCC cells by targeting the miR-665/HMGB3 axis. The NOP14-AS1/miR-665/HMGB pathway may be a valuable prognostic indicator and therapeutic target for preventing TSCC.

Platelet Migration and Bacterial Trapping Assay under Flow.

Blood platelets are critical for hemostasis and thrombosis, but also play diverse roles during immune responses. We have recently reported that platelets migrate at sites of infection in vitro and in vivo. Importantly, platelets use their ability to migrate to collect and bundle fibrin (ogen)-bound bacteria accomplishing efficient intravascular bacterial trapping. Here, we describe a method that allows analyzing platelet migration in vitro, focusing on their ability to collect bacteria and trap bacteria under flow.

Clinical correlates and heritability of flow-mediated dilation in the community: the Framingham Heart Study.

BACKGROUND: Studies in selected samples have linked impaired endothelial function with cardiovascular disease and its risk factors. The clinical correlates and heritability of endothelial function in the community have not been described. METHODS AND RESULTS: We examined a measure of endothelial function, brachial artery flow-mediated dilation (FMD), expressed as both percent (FMD%) and actual dilation by ultrasound with the occlusion cuff below the elbow in 2883 Framingham Study participants (52.9% women; mean age, 61 years). A subset of 1096 participants performed a 6-minute walk test before FMD determination. Mean FMD% was 3.3+/-3.0% in women and 2.4+/-2.4% in men. In stepwise multivariable linear regression models, FMD% was inversely related to age, systolic blood pressure, body mass index (BMI), lipid-lowering medication, and smoking, whereas it was positively related to female gender, heart rate, and prior walk test. The estimated heritability of FMD% was 0.14. FMD actual dilation findings were similar, except that female sex and BMI were not significantly associated. CONCLUSIONS: Increasing age, systolic blood pressure, BMI, and smoking were associated with lower FMD% in our community-based sample, whereas prior exercise and increasing heart rate were associated with higher FMD%. The estimated heritability of FMD was modest. Future research will permit more complete characterization of the genetic and environmental determinants of endothelial function and its prognostic value in the community.

Brachial artery vasodilator function and systemic inflammation in the Framingham Offspring Study.

BACKGROUND: In experimental studies, traditional risk factors and proinflammatory processes alter the regulatory functions of the vascular endothelium to promote atherosclerosis. These alterations include expression of leukocyte adhesion molecules and decreased bioavailability of endothelium-derived nitric oxide, an important regulator of vascular homeostasis and tone. The precise relations among risk factors, inflammation, and nitric oxide bioavailability remain uncertain. METHODS AND RESULTS: To test the hypothesis that inflammation impairs endothelial function in humans, we measured brachial artery flow-mediated dilation, reactive hyperemia, and serum concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), soluble intracellular adhesion molecule-1 (sICAM-1), and monocyte chemotactic protein-1 (MCP-1) in 2701 participants from the Framingham Study (mean age 61 years, 53% women). There were modest unadjusted inverse correlations between flow-mediated dilation and CRP, IL-6, and sICAM-1 (P<0.001 for all) that were rendered nonsignificant after accounting for traditional coronary risk factors. For reactive hyperemia, we observed inverse correlations with markers of inflammation in unadjusted models that were attenuated 57% to 74% after accounting for risk factors. However, partial correlations of CRP, IL-6, and sICAM-1 with reactive hyperemia remained significant. CONCLUSIONS: Our observations are consistent with the hypothesis that risk factors induce a state of inflammation that impairs vascular function. For flow-mediated dilation, we found no evidence that inflammation has additional effects beyond those attributable to traditional risk factors. The incremental contribution of CRP, IL-6, and sICAM-1 to reactive hyperemia above and beyond known risk factors suggests that systemic inflammation may contribute to impaired vasomotor function in forearm microvessels.

Naoxintong protects against atherosclerosis through lipid-lowering and inhibiting maturation of dendritic cells in LDL receptor knockout mice fed a high-fat diet.

Naoxintong (NXT), a Chinese Materia Medica standardized product, extracted from 16 various kinds of Chinese traditional herbal medicines including Salvia miltiorrhiza, Angelica sinennsis, Astragali Radix, is clinically effective in treating atherosclerosisrelated diseases. Here, we tested the hypothesis that the anti-atherosclerosis effects of NXT might be mediated by suppressing maturation of dendritic cells (DCs) in a mice model of atherosclerosis. LDLR(-/-) mice fed a high-fat diet were treated with placebo, NXT (0.7 g/kg/d, oral diet) or simvastatin (100mg/kg/d, oral diet) for 8 weeks, respectively. NXT treatment significantly reduced plasma triglyceride (112 ± 18 mg/dl vs. 192 ± 68 mg/dl, P<0.05) and total cholesterol (944 ± 158 mg/dl vs. 1387 ± 208 mg/dl, P<0.05) compared to placebo treatment. Vascular lesions were significantly smaller and macrophage content and amount of DCs in plaques were significantly less in NXT and simvastatin groups than in placebo group (all P<0.05). In addition, expressions of splenic DC membrane molecules (CD40, CD86 and CD80) and the plasma level of IL-12p70 were significantly lower in NXT and simvastatin groups than in placebo group. In conclusion, NXT protects against atherosclerosis through lipid-lowering and inhibiting DCs maturation in this mice model of atherosclerosis.

Brachial artery diameter, blood flow and flow-mediated dilation in sleep-disordered breathing.

Clinic-based, case-control studies linked sleep-disordered breathing (SDB) to markers of endothelial dysfunction. We attempted to validate this association in a large community-based sample, and evaluate the relation of SDB to arterial diameter and peripheral blood flow. This community-based, cross-sectional observational study included 327 men and 355 women, aged 42-83 years, from the Framingham Heart Study site of the Sleep Heart Health Study. The polysomnographically derived apnea-hypopnea index and the hypoxemia index (percent sleep time with oxyhemoglobin saturation below 90%) were used to quantify the severity of SDB. Brachial artery ultrasound measurements included baseline diameter, percent flow-mediated dilation, and baseline and hyperemic flow velocity and volume. The baseline brachial artery diameter was significantly associated with both the apnea-hypopnea index and the hypoxemia index. The association was diminished by adjustment for body mass index, but remained significant for the apnea-hypopnea index. Age-, sex-, race- and body mass index-adjusted mean diameters were 4.32, 4.33, 4.33, 4.56, 4.53 mm for those with apnea-hypopnea index < 1.5, 1.5-4.9, 5-14.9, 15-29.9, >/= 30, respectively; p = 0.03. Baseline flow measures were associated with the apnea-hypopnea index but this association was non-significant after adjusting for body mass index. No significant association was observed between measures of SDB and percent flow-mediated dilation or hyperemic flow in any model. In conclusion, this study supports a moderate association of SDB and larger baseline brachial artery diameter, which may reflect SDB-induced vascular remodeling. This study does not support a link between SDB and endothelial dysfunction as measured by brachial artery flow-mediated dilation.