Zhaowei Zhu

Hypoxic Trophoblast HMGB1 Induces Endothelial Cell Hyperpermeability via the TRL-4/Caveolin-1 Pathway

High mobility group box 1 (HMGB1) plays an important role in the pathologic processes of endothelial permeability under oxidative stress. Trophoblast oxidative stress has been implicated in the pathophysiology of preeclampsia (PE). HMGB1 serum levels are increased in PE. However, the potential roles of HMGB1 in endothelial permeability in PE remain unclear. We assessed the effects of the hypoxic trophoblast on the permeability of the endothelial monolayer. Our results showed that the hypoxic trophoblast displayed higher HMGB1 mRNA, intracellular HMGB1 protein, and HMGB1 in conditioned medium than those of the normoxic trophoblast did. The hypoxic trophoblast conditioned medium increased the endothelial monolayer permeability and increased TLR 4 and caveolin-1 (CAV-1) protein expression in endothelial cells, which was inhibited by glycyrrhizic acid and HMGB1 small interfering RNA transfection to trophoblasts before hypoxia. The increased endothelial permeability induced by hypoxic trophoblast conditioned medium could be inhibited with TLR4 or CAV-1 gene silencing in endothelial cells. Immunoprecipitation showed that CAV-1 and TLR4 are colocalized in HUVECs and C57BL/6 mouse kidney. TLR4 small interfering RNA suppressed CAV-1 protein expression in endothelial cells upon stimulation of hypoxic trophoblast conditioned medium or HMGB1. We conclude that hypoxic trophoblasts play an important role in the mechanism of general edema (including protein urine) in PE via increasing endothelial monolayer permeability through the HMGB1/TLR4/CAV-1 pathway.

Inhibition of PKR impairs angiogenesis through a VEGF pathway

Peripheral artery disease (PAD) is a common clinical problem, and its pathophysiological mechanisms are incompletely understood. Double-stranded RNA-activated protein kinase (PKR) is a ubiquitously expressed serine/threonine protein kinase. Although PKR has been reported in antivirus and the immune system, the role of PKR in vascular function, especially in angiogenesis, is still unclear. PKR(-/-) mice were used in our experiments. Blood flow recovery was significantly delayed in PKR(-/-) vs. WT mice (Laser Doppler detection, n = 9, P < 0.01), accompanied by 34% reduced CD31-positive stain in ischemic muscle 28 days after procedure (immunohistochemistry, n = 9, P < 0.05). PKR expression decreased in the first 12 h and increased to peak at 24 h in human umbilical vein endothelial cells (HUVECs) in response to hypoxia (Western blot analyses, n = 3, P < 0.05). Accordingly, phospho-PKR expression increased in HUVECs 24 h after treatment with hypoxia (Western blot analyses, n = 3, P < 0.05). Inhibition of PKR (siRNA transfection) reduced microtubule formation (Matrigel tube formation, n = 3, vs. control siRNA, P < 0.05) and migration (wound healing, n = 3, vs. control siRNA, P < 0.05) by 33 and 59%, respectively. Vascular endothelial growth factor (VEGF) expression in ischemic muscle from PKR(-/-) mice was significantly decreased by 54% 1 day after procedure (n = 3, P < 0.05, vs. WT) and by 63% 7 days after procedure (n = 3, P < 0.01, vs. WT), respectively. At the same time, VEGF expression in HUVECs decreased by 21% (n = 3, P < 0.05, PKR siRNA vs. control siRNA). These findings demonstrate that PKR mediates angiogenesis through a VEGF pathway, which may form the basis for future intervention of PAD.

Elevated serum HMGB1 in pulmonary arterial hypertension secondary to congenital heart disease

AIMSnThis study investigated the potential value of serum high mobility group box-1 (HMGB1) level in the diagnosis, staging and treatment response of patients with pulmonary arterial hypertension secondary to congenital heart disease (PAH-CHD).nnnMETHODS AND RESULTSnThis was a single-center prospective study in 106 CHD patients. Serum HMGB1 levels were measured by enzymelinked immunosorbent assay. HMGB1 levels were significantly increased in patients with PAH compared to patients without PAH (P<0.01) and healthy controls (P<0.001). HMGB1 levels significantly correlated with pulmonary arterial pressure (P<0.001) and pulmonary vascular resistance (PVR) (P<0.001). In patients with severe PAH, HMGB1 levels were significantly higher in patients with Eisenmenger syndrome (ES) than in patients exhibiting low PVR (P<0.001). Severe PAH and ES was identified by serum HMGB1 with a cutoff value of 13.62ng/mL (P<0.001) with a specificity of 82.8% and a sensitivity of 90%, and a cutoff value of 21.62ng/mL (P=0.001) with a specificity of 85.2% and a sensitivity of 64.3%, respectively. HMGB1 levels were significantly decreased after sildenafil therapy for 6months (P<0.01).nnnCONCLUSIONSnOur study suggests that serum HMGB1 level may be used as a biomarker to identify PAH in CHD patients, assess pulmonary vascular remodeling, and evaluate the treatment response to sildenafil.

Platelet reactivity-adjusted antiplatelet therapy in patients with percutaneous coronary intervention: a meta-analysis of randomized controlled trials

Abstract Numerous number of evidences show that high on-treatment platelet reactivity is a well-known risk factor for adverse events in patients after percutaneous coronary intervention (PCI). Controversial situations still exist regarding the effectiveness of tailoring antiplatelet therapy according to platelet function monitoring. The PubMed, Embase, and Cochrane Central databases were searched for randomized trials comparing platelet reactivity-adjusted antiplatelet therapy with conventional antiplatelet therapy in patients undergoing PCI. The primary end point was all-cause mortality, major adverse cardiac events (MACE) including cardiovascular (CV) death, nonfatal myocardial infarction (MI), definite/probable stent thrombosis (ST), revascularization, and stroke or transient ischemic attack (TIA). The safety end point was defined as major bleeding events. We derived pooled risk ratios (RRs) with fixed-effect models. Six studies enrolling 6347 patients were included. Compared with conventional treatment, tailoring antiplatelet failed to reduce all-cause mortality (RR: 0.89, 95% confidence interval [CI]: 0.63–1.24, P = 0.48), MACE (RR: 1.02, 95% CI: 0.92–1.14, P = 0.69), MI (RR: 1.07, 95% CI: 0.95–1.21, P = 0.24), CV death (RR: 0.69, 95% CI: 0.40–1.19, P = 0.09), ST (RR: 0.83, 95% CI: 0.50–1.38, P = 0.23), stroke or TIA (RR: 1.08, 95% CI: 0.55–2.12, P = 0.83), revascularization (RR: 0.96, 95% CI: 0.69–1.33, P = 0.79), and major bleeding events (RR: 0.79, 95% CI: 0.53–1.17, P = 0.24). Compared with traditional antiplatelet treatment, tailoring antiplatelet therapy according to platelet reactivity testing failed to reduce all-cause mortality, MACE, and major bleeding events in patients undergoing PCI.

Effects of thrombolysis on outcomes of patients with deep venous thrombosis: An updated meta-analysis

Background Small randomized controlled studies and meta-analyses have shown that thrombolysis, especially catheter-directed thrombolysis, can reduce the incidence of post-thrombotic syndrome (PTS). However, the recent ATTRACT trial did not demonstrate the same effects. Given this confusing situation, we performed an updated meta-analysis of randomized controlled trials (RCTs) to evaluate the effects of thrombolysis, especially catheter-directed thrombolysis, on the outcomes of deep venous thrombosis (DVT). Methods We searched PubMed, Embase, and the Cochrane Library for relevant studies comparing thrombolysis in combination with anticoagulation and with anticoagulation alone. The primary endpoint was PTS during the longest follow-up period. The safety endpoint was the incidence of major bleeding events. We also evaluated the outcomes of catheter-directed thrombolysis as a subgroup analysis. Results Six RCTs, including 1418 patients with DVT, were included in our meta-analysis. Thrombolysis in combination with anticoagulation did not reduce PTS (RR: 0.90, [0.80–1.01], P = 0.19) and increased major bleeding (RR: 2.07, [1.12–3.81], P = 0.02). However, trial sequential analysis (TSA) showed that more patients are needed to support the conclusion that thrombolysis in combination with anticoagulation increased major bleeding. Catheter-directed thrombolysis did not reduce the incidence of PTS (RR: 0.88, [0.68–1.13], P = 0.31) and did increase the incidence of major bleeding events (RR: 1.89, [1.00–3.59], P = 0.05). Conclusion Thrombolysis, including catheter-directed thrombolysis, did not reduce the incidence of PTS and increased the incidence of major bleeding. However, the results were not supported by TSA and sensitivity analysis, so more relevant studies are needed.