Ixonnexin from Tick Saliva Promotes Fibrinolysis by Interacting with Plasminogen and Tissue-Type Plasminogen Activator, and Prevents Arterial Thrombosis

Tick saliva is a rich source of modulators of vascular biology. We have characterized Ixonnexin, a member of the "Basic-tail" family of salivary proteins from the tick Ixodes scapularis. Ixonnexin is a 104 residues (11.8 KDa), non-enzymatic basic protein which contains 3 disulfide bonds and a C-terminal rich in lysine. It is homologous to SALP14, a tick salivary FXa anticoagulant. Ixonnexin was produced by ligation of synthesized fragments (51-104) and (1-50) followed by folding. Ixonnexin, like SALP14, interacts with FXa. Notably, Ixonnexin also modulates fibrinolysis in vitro by a unique salivary mechanism. Accordingly, it accelerates plasminogen activation by tissue-type plasminogen activator (t-PA) with Km 100 nM; however, it does not affect urokinase-mediated fibrinolysis. Additionally, lysine analogue ε-aminocaproic acid inhibits Ixonnexin-mediated plasmin generation implying that lysine-binding sites of Kringle domain(s) of plasminogen or t-PA are involved in this process. Moreover, surface plasmon resonance experiments shows that Ixonnexin binds t-PA, and plasminogen (KD 10 nM), but not urokinase. These results imply that Ixonnexin promotes fibrinolysis by supporting the interaction of plasminogen with t-PA through formation of an enzymatically productive ternary complex. Finally, in vivo experiments demonstrates that Ixonnexin inhibits FeCl3-induced thrombosis in mice. Ixonnexin emerges as novel modulator of fibrinolysis which may also affect parasite-vector-host interactions.

CdS nanoparticles of different lengths induce differential responses in some of the liver functions of mice

Cadmium sulfide nanoparticles (CdS NPs) are one of important nanoparticle materials which are widely used in photoelectric production, but their potential health hazard to the liver is not clear. This study is aimed at exploring the possible mechanisms of liver injury induced by CdS NPs. Male mice were treated with nanoparticles of 110-130 nm and 80-100 nm cadmium sulfide. The main methods were based on detecting the vigor of superoxide dismutase (SOD) and glutathione (GSH), and content of malondialdehyde (MDA) in both blood and liver tissues as well as on observing the pathological changes in liver tissue. CdS NPs suppressed the activity of SOD and GSH, and increased the serum MDA content (p < 0.05); both effects were observed together in liver tissues of 80-100 nm group (p < 0.05) and were accompanied by an obviously inflammatory response. CdS NPs induced oxidative damage and inflammatory response in liver tissue, which may be an underlying mechanism for its pulmonary toxicity. Additionally, the toxicity of CdS NPs was closely related to the size of nanoparticles. Pathological results showed that the hepatotoxicity of shorter CdS NPs is greater than that of longer CdS NPs (Tab. 6, Fig. 3, Ref. 20).

Abstract P2-06-03: Clinicopathologic characteristics and genomic essence analyses revealed estrogen receptor positive, progesterone receptor negative and human epidermal growth factor receptor 2 negative breast cancer to be more basal-like and endocrine resistant

Background: Estrogen receptor positive/ progesterone receptor negative/ human epidermal growth factor receptor 2 negative (ER+/PR-/HER2-) tumors define a distinct subtype of ER+ breast cancer, characterized by poor response to endocrine therapy and poor prognosis. The genomic landscape of ER+/PR-/HER2- tumor has yet to be systematically studied,and driver events for tumor progression and endocrine resistance with loss of PR expression are yet to be identified. Methods: We assessed 13,410 ER+/PR-/HER2- patients from Surveillance, Epidemiology, and End Results (SEER), the Cancer Genome Atlas (TCGA) and Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) for clinicopathologic characteristics, survival and genomic analyses. Patients were divided into endocrine-resistant and endocrine-sensitive groups using an endocrine therapy sensitivity score [(0.8*ER+1.2*PGR+BCL2+SCUBE2)/4], and we further explored genomic events enriched in the endocrine-resistant group. Results: Clinicopathologic features and survival outcomes of ER+/PR-/HER2- patients were worse than ER+/PR+/HER2- in SEER and METABRIC cohort. The genomic landscape of ER+/PR-/HER2- tumors revealed them to have more aggressive properties, like a higher percentage of luminal B (29-35%) and basal-like (4-16%) subtypes; more intClust subtypes with high genomic instability (intClust1, 6); more TP53 mutation and less PIK3CA mutation; and more copy number variation events. ER+/PR-/HER2- tumors have more focal amplification events, including 8p11.23 (ZNF703) and 17q23.1 (RPS6KB1) and more focal deletion events, such as 17q21.31 (BRCA1) and 14q24.3 (MLH3). Pathifier pathway analyses showed that up-regulated pathways in ER+/PR-/HER2-tumors included those associated with biosynthesis, metabolism, drug resistance and DNA replications (FDR&lt;0.1). Endocrine sensitivity score for ER+/PR-/HER2- group was significantly lower than ER+/PR+/HER2- group. When split by 1st quartile of endocrine sensitivity score, up to 72.7% of ER+/PR-/HER2- tumors were grouped into the endocrine-resistant group. Mutant-allele tumor heterogeneity (MATH) score is significantly lower in the endocrine-resistant group. Several focal SCNA events were more common in the endocrine-resistant group (P&lt;0.05), including 8q24.21 amplification with only the MYC gene in the “peak” region. Pathways unregulated in the endocrine-resistant group of ER+/PR-/HER2- tumor included MYC pathway and mTORC1 signaling (FDR&lt;0.25). Conclusion: ER+/PR-/HER2- breast cancer was a heterogeneous tumor group and featured more basal-like and luminal B characteristics. The ER+/PR-/HER2- tumors are relatively resistant to endocrine therapy, and MYC pathway enrichment and corresponding 8q24.21 amplification might be one of the drug-resistance mechanisms. Our study provides an overall understanding of the distinct genomic landscape of ER+/PR-/HER2- breast cancer. Further investigations into the pathways activated with the loss of PR expression may provide clues for novel changes in the therapeutic regimens of ER+/PR-/HER2- breast cancer.

Citation Format: Liu X, Ma D, Jiang Y-Z, Liu Y-R, Yu K-D, Shao Z-M. Clinicopathologic characteristics and genomic essence analyses revealed estrogen receptor positive, progesterone receptor negative and human epidermal growth factor receptor 2 negative breast cancer to be more basal-like and endocrine resistant [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-06-03.

Correction to: Gene mutation spectrum and genotype-phenotype correlation in a cohort of Chinese osteogenesis imperfecta patients revealed by targeted next generation sequencing

In Table 2:Family 6 should be c.643-13_662delCTATCTTTTCTAGGGTCCCATGGGTCCCCGAGG instead of c.643-13_662delCTATCTTTTCTAGGGTCCCATGGGTCCCC.Family 33 should be c.271_279dupGCCCTCTCG instead of c.271_279dupGCCCTCT.In the 2nd para. of the Molecular diagnosis, section t(5;8)(q32;q21) should be t(5;7)(q32;q21).

Gene mutation spectrum and genotype-phenotype correlation in a cohort of Chinese osteogenesis imperfecta patients revealed by targeted next generation sequencing

The achievement of more accurate diagnosis would greatly benefit the management of patients with osteogenesis imperfecta (OI). In this study, we present the largest OI sample in China as screened by next generation sequencing. In particular, we successfully identified 81 variants, which included 45 novel variants. We further did a genotype-phenotype analysis, which helps make a better understanding of OI.

INTRODUCTION

This study aims to reveal the gene mutation spectrum and the genotype-phenotype relationship among Chinese OI patients by next generation sequencing (NGS).

METHODS

We developed a NGS-based panel for targeted sequencing of all exons of 14 genes related to OI, and performed diagnostic gene sequencing for a cohort of 103 Chinese OI patients from 101 unrelated families. Mutations identified by NGS were further confirmed by Sanger sequencing and co-segregation analysis.

RESULTS

Of the 103 patients from 101 unrelated OI families, we identified 79 mutations, including 43 novel mutations (11 frameshift, 17 missense, 5 nonsense, 9 splice site, and 1 chromosome translocation) in 90 patients (87.4%). Mutations in genes encoding type I collagen, COL1A1 (n = 37), and COL1A2 (n = 29) accounts for 73.3% of all molecularly diagnosed patients, followed by IFITM5 (n = 9, 10%), SERPINF1 (n = 4, 4.4%), WNT1 (n = 4, 4.4%), FKBP10 (n = 3, 3.3%), TMEM38B (n = 3, 3.3%), and PLOD2 (n = 1, 1.1%). This corresponds to 75 autosomal dominant inherited (AD) OI patients and 15 autosomal recessive (AR) inherited patients. Compared with AD inherited OI patients, AR inherited patients had lower bone mineral density (BMD) at spine (P = 0.05) and less frequent blue sclera (P = 0.001). Patients with type I collagen qualitative defects had lower femoral neck BMD Z-score (P = 0.034) and were shorter compared with patients with type I collagen quantitative defects (P = 0.022).

CONCLUSION

We revealed the gene mutation spectrum in Chinese OI patients, and novel mutations identified here expanded the mutation catalog and genotype and phenotype relationships among OI patients.

Inflammatory monocytes expressing tissue factor drive SIV and HIV coagulopathy

In HIV infection, persistent inflammation despite effective antiretroviral therapy is linked to increased risk of noninfectious chronic complications such as cardiovascular and thromboembolic disease. A better understanding of inflammatory and coagulation pathways in HIV infection is needed to optimize clinical care. Markers of monocyte activation and coagulation independently predict morbidity and mortality associated with non-AIDS events. We identified a specific subset of monocytes that express tissue factor (TF), persist after virological suppression, and trigger the coagulation cascade by activating factor X. This subset of monocytes expressing TF had a distinct gene signature with up-regulated innate immune markers and evidence of robust production of multiple proinflammatory cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and IL-6, ex vivo and in vitro upon lipopolysaccharide stimulation. We validated our findings in a nonhuman primate model, showing that TF-expressing inflammatory monocytes were associated with simian immunodeficiency virus (SIV)-related coagulopathy in the progressive [pigtail macaques (PTMs)] but not in the nonpathogenic (African green monkeys) SIV infection model. Last, Ixolaris, an anticoagulant that inhibits the TF pathway, was tested and potently blocked functional TF activity in vitro in HIV and SIV infection without affecting monocyte responses to Toll-like receptor stimulation. Strikingly, in vivo treatment of SIV-infected PTMs with Ixolaris was associated with significant decreases in D-dimer and immune activation. These data suggest that TF-expressing monocytes are at the epicenter of inflammation and coagulation in chronic HIV and SIV infection and may represent a potential therapeutic target.

Association between bone mineral density, muscle strength, and vitamin D status in patients with myasthenia gravis: a cross-sectional study

Myasthenia gravis (MG) patients had low proximal hip BMD, which could be explained by reduced muscle strength, elevated bone resorption markers, vitamin D deficiency, and increased PTH levels in those with MG compared to controls.

INTRODUCTION

Muscle strength is closely correlated with bone mineral density (BMD) and vitamin D status. Here, we evaluated muscle strength, BMD, and vitamin D status in a large sample of Chinese patients with MG.

METHODS

In this cross-sectional survey, 86 patients with MG without glucocorticoid treatment and 86 healthy controls were included. Serum levels of 25-hydroxyvitamin D [25OHD], parathyroid hormone (PTH), bone turnover markers (BTMs), and BMD were measured and compared between the two groups. Grip strength and one-leg standing time (OLST) were also assessed in MG patients.

RESULTS

Low grip strength and short OLST were found in 11 (12.8%) and 12 (14.0%) MG patients, respectively. There were 3 (3.5%) MG patients with low bone mass for chronological age. Serum beta C-terminal telopeptide and PTH levels were higher (p < 0.001 and p = 0.001, respectively), and BMD at the femoral neck and trochanter were lower in MG patients (p < 0.001 and p < 0.001, respectively) compared to healthy controls. In patients with MG, grip strength was positively correlated with BMD. Serum 25OHD levels were lower in MG patients than in healthy controls (17.36 ± 6.64 vs. 22.11 ± 7.28 ng/ml, p < 0.001).

CONCLUSION

Grip strength was positively correlated with BMD in Chinese patients with MG. MG patients tended to have low proximal hip BMD, which may partially be explained by reduced muscle strength, vitamin D deficiency, increased PTH levels, and elevated bone resorption markers compared to controls.

Modeling the Blood-Brain Barrier in a 3D triple co-culture microfluidic system

The need for a blood-brain barrier (BBB) model that accurately mimics the physiological characteristics of the in-vivo situation is well-recognized by researchers in academia and industry. However, there is currently no in-vitro model allowing studies of neuronal growth and/or function influenced by factors from the blood that cross through the BBB. Therefore, we established a 3D triple co-culture microfluidic system using human umbilical vein endothelial cells (HUVEC) together with primary rat astrocytes and neurons. Immunostaining confirmed the successful triple co-culture system consisting of an intact BBB with tight intercellular junctions in the endothelial monolayer. The BBB selective permeability was determined by a fluorescent-based assay using dextrans of different molecular weights. Finally, neuron functionality was demonstrated by calcium imaging.

Abstract P1-06-07: Clinical and molecular relevance of intra-tumor genetic heterogeneity in breast cancer: Integrative analysis of data from The Cancer Genome Atlas

Background: Intra-tumor heterogeneity (ITH) plays a pivotal role in driving breast cancer progression and therapeutic resistance. Emerging evidence has indicated that the extent of genetic heterogeneity may serve as a clinically useful biomarker. While several studies have suggested the prognostic value of ITH in several cancer types, the clinical significance of genetic ITH and molecular portraits that correlated with different ITH levels were poorly understood in breast cancer. The establishment of algorithms estimating genetic ITH based on sequencing of bulk tumor DNA offered us an opportunity to explore the clinical implication of ITH in large breast cancer cohorts and, for the first time, to use integrative genomic analyses to reveal molecular portraits related to intra-tumor genetic heterogeneity.

Methods: We assessed 916 female breast cancer patients from The Cancer Genome Atlas. Mutant-allele tumor heterogeneity (MATH) values were calculated from whole-exome sequencing data. We used integers nearest to the tertiles of the MATH values as cutoff points to divide the patients into three groups nearly equal in size. The association between MATH value and clinical characteristics was evaluated, followed by survival analyses in these different MATH groups. We then compared the rates of total non-silent somatic mutations among the different MATH groups, and further determined the mutations independently associated with high MATH by logistic regression adjusting for T classification and clinical subtypes. Similar methods, superadding somatic copy number alteration (SCNA) burden in logistic model, were used to evaluate SCNA events that were significantly associated with high MATH level. Gene enrichment between the high and rest MATH groups was analyzed using Gene Set Enrichment Analysis.

Results: The patients were divided into low (MATH value lower than 33), intermediate (MATH between 33 and 46) and high (MATH higher than 46) MATH groups. High T stage, African American race, and triple-negative or basal-like subtype were associated with a higher MATH level (all P&lt;0.001). In hormone receptor-positive and human epidermal growth factor receptor-negative patients, the high MATH group showed a tendency toward a worse overall survival (P=0.052); however, while in triple-negative breast cancer, both high and low MATH indicated a worse outcome (P=0.032). Furthermore, the TP53 mutation rate increased as MATH was elevated (P&lt;0.001), whereas CDH1 mutations were correlated with a lower level of MATH (P=0.002). Several focal and arm-level SCNA events were more common in the high MATH group, including Chr8q24 with only the MYC gene in the “peak” region. Similarly, high MATH was associated with gene set enrichment related to the MYC pathway and proliferation.

Conclusion: Our study extended the knowledge concerning the clinical role of ITH in breast cancer, especially the distinct pattern of prognostic values in different clinical subtypes, which may help promote the clinical utilization of genetic ITH. Our attempt at exploring the molecular features related to ITH might provide clues for the source and consequences of ITH, inspiring subsequent experiments investigating the laws underling tumor heterogeneity.

Citation Format: Ma D, Jiang Y-Z, Liu X-Y, Liu Y-R, Yu K-D, Shao Z-M. Clinical and molecular relevance of intra-tumor genetic heterogeneity in breast cancer: Integrative analysis of data from The Cancer Genome Atlas [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-06-07.

Compacting a Single Flow Diverter versus Overlapping Flow Diverters for Intracranial Aneurysms: A Computational Study

BACKGROUND AND PURPOSE

Locally compacting the mesh of a flow diverter by a dynamic push-pull technique can accelerate intracranial aneurysm healing. We asked how this deployment strategy compares with overlapping 2 flow diverters for aneurysmal flow reduction.

MATERIALS AND METHODS

Using a high-fidelity virtual stent placement method, we simulated 3 flow-diverter strategies (single noncompacted, 2 overlapped, and single compacted) in 3 aneurysms (fusiform, large saccular, and medium saccular). Computational fluid dynamics analysis provided posttreatment hemodynamic parameters, including time-averaged inflow rate, aneurysm-averaged velocity, wall shear stress, total absolute circulation, and turnover time. We examined the relationship between the achieved degree of compaction and aneurysm orifice area.

RESULTS

Flow-diverter compaction resulted in a compaction coverage of 57%, 47%, and 22% over the orifice of the fusiform, large, and medium saccular aneurysm, respectively. Compaction coverage increased linearly with orifice area. In the fusiform aneurysm, the single compacted flow diverter accomplished more aneurysmal flow reduction than the other 2 strategies, as indicated by all 5 hemodynamic parameters. In the 2 saccular aneurysms, the overlapped flow diverters achieved the most flow reduction, followed by the single compacted and the noncompacted flow diverter.

CONCLUSIONS

Compacting a single flow diverter can outperform overlapping 2 flow diverters in aneurysmal flow reduction, provided that the compaction produces a mesh denser than 2 overlapped flow diverters and this denser mesh covers a sufficient portion of the aneurysm orifice area, for which we suggest a minimum of 50%. This strategy is most effective for aneurysms with large orifices, especially fusiform aneurysms.

Structural predictions for curli amyloid fibril subunits CsgA and CsgB

CsgA are the building blocks of curli fibrils.