Pleiotropic effects of survivin in vascular endothelial cells

Association of BIRC5 Gene Polymorphism with the Collateral Circulation and Severity of Large Artery Atherosclerotic Stroke

OBJECTIVES

The collateral circulation near the cerebral artery occlusion can contribute to the relief of the symptoms and signs of stroke. Genetic factors play a decisive role in the difference in collateral circulation. Survivin, encoded by the baculoviral inhibitor of apoptosis (IAP) repeat-containing 5 gene (BIRC5), plays an important role in maintaining long-term endothelial integrity and homeostasis and as an angiogenic factor in the treatment of vascular diseases. We hypothesized that genetic variations in the BIRC5 gene may contribute to severity by influencing the collateral circulation. This study aimed at examining how the polymorphism of the BIRC5 gene correlated with the collateral circulation and severity of large artery atherosclerotic stroke.

METHODS

This study enrolled 428 patients with large artery atherosclerotic stroke. There are no statistical differences in age, sex, social behavior, such as smoking and drinking, between the groups classified by the collateral circulation and by the severity of stroke (P > 0.01). Direct sequencing was performed for the genotyping of single nucleotide polymorphism (SNP) of BIRC5 (rs2071214). The enrolled patients were divided into several subgroups based on the collateral flow grading system from the American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR), the results of the National Institutes of Health Stroke Survey (NIHSS) (6 as a threshold), and the score of the modified Rankin scale (mRS) (for the prediction of prognosis, 2 as a threshold). Differences among subgroups were identified through logistic regression.

RESULTS

The analysis of collateral circulation revealed the significant correlation of SNP of rs2071214 with the development of poor collateral circulation of large artery atherosclerotic stroke in the additive model (GG vs. AA, odds ratio (OR) = 3.592, 95% confidence interval (CI) = 1.410-9.150, and P=0.007) and the recessive model (GG vs. AA/GA, OR = 3.313, 95% CI = 1.420-7.727, and P=0.006). The analysis of stroke severity exposed the significant role of the SNP of rs2071214 in increasing stroke severity in the dominant model (GA/GG vs. AA, OR = 1.658, 95% CI = 1.017-2.703, and P=0.043) and the additive model (GA vs. AA, OR = 1.717, 95% CI = 1.021-2.888, and P=0.042). However, the analysis of the short-term outcome indicated that three genetic models were not associated with short-term outcomes in the additive model (GA vs. AA, P=0.815, GG vs. AA, and P=0.336), the dominant model (GA/GG vs. AA and P=0.589), and the recessive model (GG vs. AA/GA and P=0.342).

CONCLUSION

Our findings identified the SNP of rs2071214 of the BIRC5 gene as a risk factor for the poor compensatory ability of collateral circulation and a predictor of stroke severity in large artery atherosclerotic stroke, which suggested that the SNP of rs2071214 can serve as an innovative therapeutic target for patients with acute ischemic stroke.

Combined Analysis of Surface Protein Profile and microRNA Expression Profile of Exosomes Derived from Brain Microvascular Endothelial Cells in Early Cerebral Ischemia

Endothelial cell damage is an important pathological basis for the deterioration of acute ischemia stroke. Our previous studies have been exploring the mechanism of blood-brain barrier (BBB) endothelial cell injury in the early stage of cerebral ischemia. Exosomes act as an important intercellular player in neurovascular communication. However, the characteristic of exosomes derived from BBB endothelial cells in early ischemic stroke is poorly understood. We exposed cultured brain microvascular endothelial cells (bEnd.3) to 3 h oxygen glucose deprivation (OGD) to mimic early cerebral ischemia in vitro and compared miRome and surface protein contents of exosomes derived from bEnd.3 cells by miRNA sequencing and the proximity barcoding assay (PBA). A total of 346 differentially miRNA (159 upregulated and 187 downregulated) were identified via miRNA-Seq in bEnd.3 cells after exposure to OGD for 3 h. Moreover, Gene Ontology (GO) and KEGG pathway analyses showed that cell proliferation- and angiogenesis-associated miRNAs were significantly affected. The abnormal changes in top eight miRNAs were further verified by a quantitative polymerase chain reaction (qPCR). PBA experiments showed that the numbers of exosomes carrying the following proteins increased significantly under ischemia, including bFGF, CD146, EPHA2, ABCB5, and ITGB2. These proteins were related to angiogenesis, cell proliferation, and cell inflammation. The network analysis combining PBA data with miRNA-Seq data showed that 79 miRNAs were related to 24 membrane proteins and predicted that there were surface proteins associated with a variety of miRNA molecules, such as ITGA9, XIAP, ADAM1, ITGA2, ITGA3, PDPN, and ITGB1. Meanwhile, there were miRNAs related to various surface proteins including miR-410-3p, miR-378b, and miR-1960. Taken together, our data demonstrated for the first time the changes of exosomal miRNAs and surface protein profiles derived from ischemic microvascular endothelial cells, which may provide new therapeutic targets for BBB protection in ischemic stroke.

Multimodal Photoacoustic Imaging-Guided Regression of Corneal Neovascularization: A Non-Invasive and Safe Strategy

Corneal neovascularization (CNV) is one of the main factors that induce blindness worldwide. However, current medical treatments cannot achieve non-invasive and safe inhibition of CNV. A noninvasive photoacoustic imaging (PAI)-guided method is purposed for the regression of CNV. PAI can monitor the oxygen saturation of cornea blood vessels through the endogenous contrast of hemoglobin and trace administrated drugs by themselves as exogenous contrast agents. An indocyanine green (ICG)-based nanocomposite (R-s-ICG) is prepared for CNV treatment via eye drops and subconjunctival injections. It is demonstrated that R-s-ICG can enrich corneal tissues and pathological blood vessels rapidly with minor residua in normal eyeball tissues. Anti-CNV treatment-driven changes in the blood vessels are assessed by real-time multimodal PAI in vivo, and then a safe laser irradiation strategy through the canthus is developed for phototherapy and gene therapy synergistic treatment. The treatment leads to the efficient inhibition of CNV with faint damages to normal tissues.

Wall shear stress promotes intimal hyperplasia through the paracrine H2O2-mediated NOX-AKT-SVV axis

AIMS

Oscillatory wall shear stress (WSS)-linked oxidative stress promotes intimal hyperplasia (IH) development, but the underlying mechanisms are not completely understood.

MATERIALS AND METHODS

We used an in vivo rabbit carotid arterial stenosis model representing different levels of WSS and found that WSS was increased at 1 month with 50% stenosis and was accompanied by VSMCs proliferation and interstitial collagen accumulation. Increased WSS promoted the expression of NOX, AKT, and survivin (SVV) and the proliferation/migration of VSMCs and reduced apoptosis.

KEY FINDINGS

Our in vitro study suggested that H₂O₂ promoted proliferation and migration while suppressing apoptosis in cultured human umbilical vascular endothelial cells.

SIGNIFICANCE

We demonstrated that the elevation of WSS promotes VSMC proliferation and migration through the H₂O₂-mediated NOX-AKT-SVV axis, thereby accelerating IH development.

Nuclear survivin expression correlates with endoglin-assessed microvascularisation in laryngeal carcinoma

Aims

Survivin—a member of the family of inhibitor of apoptosis proteins that control cell division, apoptosis and metastasis—is overexpressed in virtually all human cancers, including laryngeal squamous cell carcinoma (LSCC). Recent findings also correlate survivin expression with the regulation of angiogenesis. The novel main aim of this study was a preliminary investigation into the potential role of survivin expression in LSCC neoangiogenesis, as determined by endoglin-assessed microvascular density (MVD).

Methods

Immunohistochemical expression of nuclear survivin and endoglin-assessed MVD were ascertained by image analysis in 75 consecutive LSCCs.

Results

Statistical analysis disclosed a strong direct correlation between nuclear survivin expression and MVD. Patients whose nuclear survivin expression was ≥6.0% had a significantly higher LSCC recurrence rate, and a significantly shorter disease-free survival (DFS) than those with a nuclear survivin expression <6.0%. The LSCC recurrence rate was also higher and the DFS shorter in patients with endoglin-assessed MVD ≥6.89%. The OR for recurrence was 2.79 in patients with LSCC with a nuclear survivin expression ≥6.0%, and 12.31 in those with an MVD≥6.89%.

Conclusions

Survivin-targeting strategies to enhance tumour cell response to apoptosis and inhibit tumour growth should receive more attention with a view to developing agents for use in multimodality advanced LSCC treatment, or combined with conventional chemotherapy. Given the present preliminary evidence in LSCC, survivin targeting should also be further investigated for anti-angiogenic purposes, to reduce tumour blood flow and induce cancer necrosis.