Publications

Abstract Introduction The coagulation protein tissue factor (TF) regulates inflammation and angiogenesis via its cytoplasmic domain in infection, cancer and diabetes. While TF is highly abundant in the heart and implicated in cardiac injuries and dysfunction, the contribution of its cytoplasmic domain in cardiac pathology remains unclear. Purpose We aimed to investigate the contribution of the cytoplasmic domain of TF to post-infarct myocardial injury and adverse left ventricular (LV) remodeling. Methods and results Myocardial infarction was induced by permanent occlusion of the left anterior descending coronary artery. Male mice with C57BL/Jax background were used for the study. Compared with wild-type mice, mice lacking the TF cytoplasmic domain (TFΔCT) had a higher survival rate (90.5% versus 70%, p=0.0298) during a 28-day follow-up after myocardial infarction. Among surviving mice, TFΔCT mice had better cardiac function and less LV remodeling (ESV: 114.5±13.1mL for WT, 67.06±10.8mL for TFΔCT, p<0.001; EDV: 146.6±12.4mL for WT, 99.97±11.71mL for TFΔCT, p<0.001) than wild-type mice. Bone marrow chimerism indicated that deletion of the TF cytoplasmic domain in either bone marrow-derived cells or cardiac resident cells could alleviate post-infarct cardiac dysfunction. Speckle-tracking strain analysis revealed that the overall improvement of post-infarct cardiac performance in TFΔCT mice was attributed to reduced myocardial deformation in the peri-infarct region (strain-%: 11.14±0.97 for WT, 15.34±1.10 for TFΔCT, p=0.007; strain rate-/s: 3.89±0.26 for WT, 5.18±0.21 for TFΔCT, p=0.0005). Histological analysis demonstrated that TFΔCT hearts had in the infarct area greater proliferation of endothelial cells and myofibroblasts accompanied with better scar formation. Compared with wild-type hearts, infarcted TFΔCT hearts showed less infiltration of proinflammatory cells with concomitant lower expression of protease-activated receptor-1 (PAR1)-Rac1 axis. Furthermore, infarcted TFΔCT hearts presented markedly higher peri-infarct vessel density associated with enhanced endothelial cell proliferation and higher expression of PAR2 and PAR2-associated pro-angiogenic pathway factors. Conclusions Our findings demonstrate that the TF cytoplasmic domain exacerbates post-infarct cardiac injury and adverse LV remodeling via differential regulation of inflammation and angiogenesis. Targeted inhibition of the TF cytoplasmic domain-mediated intracellular signaling may ameliorate post-infarct LV remodeling without perturbing coagulation. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): National University Health System of Singapore

Cancer cell metabolism has received increasing attention. Despite a boost in the application of clinical metabolic profiling (CMP) in cancer patients, a meta-analysis has not been performed. The primary goal of this study was to assess whether public accessibility of metabolomics data and identification and reporting of metabolites were sufficient to assess which metabolites were consistently altered in cancer patients. We therefore retrospectively curated data from CMP studies in cancer patients published during 5 recent years and used an established vote-counting method to perform a semiquantitative meta-analysis of metabolites in tumor tissue and blood. This analysis confirmed well-known increases in glycolytic metabolites, but also unveiled unprecedented changes in other metabolites such as ketone bodies and amino acids (histidine, tryptophan). However, this study also highlighted that insufficient public accessibility of metabolomics data, and inadequate metabolite identification and reporting hamper the discovery potential of meta-analyses of CMP studies, calling for improved standardization of metabolomics studies.

Comparison of photoreceptor grafts in preclinical models with incomplete or complete photoreceptor loss, showed differential transplant success with effective and impaired integration, respectively. Thus, Cpfl1/Rho-/- mice represent a potential benchmark model resembling patients with severe retinal degeneration to optimize photoreceptor replacement therapies.

<p>Effects of VEGFR-1 signaling ablation on body weight gain, immune cell infiltration and vasculature in adipose tissues during obesity.</p>

Abstract Purpose: BCR-ABL kinase inhibitors are employed successfully for chronic myeloid leukemia (CML) treatment. However, resistant disease and persistence of BCR-ABL1–independent leukemia stem and progenitor cells (LSPC) remain clinical challenges. The receptor tyrosine kinase Axl can mediate survival and therapy resistance of different cancer cells. We investigated the therapeutic potential of Axl inhibition in CML. Experimental Design: We used primary cells from patients with CML and TKI-sensitive and -resistant BCR-ABL1+ CML cell lines and a novel ponatinib-resistant cell line KCL-22 PonR. We analyzed the effects of genetic and pharmacologic Axl blockade by the small-molecule Axl inhibitor BGB324 in vitro and in vivo. In BCR-ABL1–unmutated cells, we also investigated BGB324 in combination with imatinib. Results: We demonstrate overexpression of Axl receptor tyrosine kinase in primary cells of patients with CML compared with healthy individuals and a further increase of Axl expression in BCR-ABL TKI-resistant patients. We show that Axl blockage decreased growth of BCR-ABL TKI-sensitive CML cells including CD34+ cells and exerts additive effects with imatinib via inhibition of Stat5 activation. BGB324 also inhibits BCR-ABL TKI-resistant cells, including T315I-mutated and ponatinib-resistant primary cells. BGB324 exerted therapeutic effects in BCR-ABL1 T315I-mutated and ponatinib-resistant preclinical mouse models. Notably, BGB324 does not inhibit BCR-ABL1 and consequently inhibits CML independent of BCR-ABL1 mutational status. Conclusions: Our data show that Axl inhibition has therapeutic potential in BCR-ABL TKI-sensitive as well as -resistant CML and support the need for clinical trials. Clin Cancer Res; 23(9); 2289–300. ©2016 AACR.

Infection outcomes are regulated by neutrophil responses to oxygen and nutrient availability.

Recently, mutations in the progranulin (PGRN) gene were found to cause familial and apparently sporadic frontotemporal lobe dementia (FTLD). Moreover, missense changes in PGRN were identified in patients with motor neuron degeneration, a condition that is related to FTLD. Most mutations identified in patients with FTLD until now have been null mutations. However, it remains unknown whether PGRN protein levels are reduced in the central nervous system from such patients. The effects of PGRN on neurons also remain to be established. We report that PGRN levels are reduced in the cerebrospinal fluid from FTLD patients carrying a PGRN mutation. We observe that PGRN and GRN E (one of the proteolytic fragments of PGRN) promote neuronal survival and enhance neurite outgrowth in cultured neurons. These results demonstrate that PGRN/GRN is a neurotrophic factor with activities that may be involved in the development of the nervous system and in neurodegeneration.

The pathophysiology of nonalcoholic steatohepatitis (NASH) should be approached as a multifactorial process. In several stages of NASH, a link between disease progression and hepatic microvasculature changes can be made. In this study we investigated the role of angiogenesis in two mouse models for NASH, and the effect of a preventive and therapeutic antiangiogenic treatment in a diet-induced mouse model for NASH. Protein and RNA levels of angiogenic and inflammatory factors were significantly up-regulated in the liver of C56BL/6 and db/db mice with NASH at different timepoints. To examine the effect of angiogenic factors on the disease progression of NASH, a prevention and treatment study was set up, blocking the placental growth factor (PlGF) or vascular endothelial growth factor receptor 2 (VEGFR2). Our study showed that treatment prevents the progression of NASH by attenuating steatosis and inflammation, both in a preventive and therapeutic setting, thereby confirming the hypothesis that angiogenic factors play an early role in the disease progression from steatosis to NASH. Anti-PlGF (αPlGF) did not significantly improve liver histology. Vascular corrosion casting showed a more disrupted liver vasculature in mice with NASH compared to controls. Treatment with αVEGFR2 showed an improvement of the liver vasculature. Moreover, fat-laden primary hepatocytes treated with αVEGFR2 stored significantly less lipids. Conclusion: Our results demonstrate that there is an increased expression of angiogenic factors in the liver in different mouse models for NASH. We found that VEGFR2 blockage attenuates steatosis and inflammation in a diet-induced mouse model for NASH in a preventive and therapeutic setting. Our findings warrant further investigation of the role of angiogenesis in the pathophysiology in NASH.

Preeclampsia, a hypertensive syndrome occurring in 3–5% of human pregnancies, has lifelong health consequences for fetuses. Cognitive ability throughout life is altered, and adult stroke risk is increased. One potential etiological factor for altered brain development is low concentrations of proangiogenic placental growth factor (PGF). Impaired PGF production may promote an antiangiogenic fetal environment during neural and cerebrovascular development. We previously reported delayed vascularization of the hindbrain, altered retinal vascular organization, and less connectivity in the circle of Willis in Pgf −/− mice. We hypothesized Pgf −/− mice would have impaired cognition and altered brain neuroanatomy in addition to compromised cerebrovasculature. Cognitive behavior was assessed in adult Pgf −/− and Pgf +/+ mice by four paradigms followed by postmortem high-resolution MRI of neuroanatomy. X-ray microcomputed tomography imaging investigated the three-dimensional cerebrovascular geometry in another cohort. Pgf −/− mice exhibited poorer spatial memory, less depressive-like behavior, and superior recognition of novel objects. Significantly smaller volumes of 10 structures were detected in the Pgf −/− compared with Pgf +/+ brain. Pgf −/− brain had more total blood vessel segments in the small-diameter range. Lack of PGF altered cognitive functions, brain neuroanatomy, and cerebrovasculature in mice. Pgf −/− mice may be a preclinical model for the offspring effects of low-PGF preeclampsia gestation.