Publications

Recent gene targeting studies indicate that the plasminogen system is implicated in cell migration and matrix degradation during arterial neointima formation and atherosclerotic aneurysm formation. This study examined whether plasmin proteolysis is involved in accelerated posttransplant arteriosclerosis (graft arterial disease). Donor carotid arteries from wild-type B10.A2R mice were transplanted into either plasminogen wild-type (Plg+/+) or homozygous plasminogen-deficient (Plg-/-) recipient mice with a genetic background of 75% C57BL/6 and 25% 129. Within 15 d after allograft transplantation, leukocytes and macrophages infiltrated the graft intima in Plg+/+ and Plg-/- recipient mice to a similar extent. In Plg+/+ recipients, the elastic laminae in the transplant media exhibited breaks through which macrophages infiltrated before smooth muscle cell proliferation, whereas in Plg-/- recipients, macrophages failed to infiltrate the transplant media which remained structurally more intact. After 45 d of transplantation, a multilayered smooth muscle cell-rich transplant neointima developed in Plg+/+ hosts, in contrast to Plg-/- recipients, in which the transplants contained a smaller intima, predominantly consisting of leukocytes, macrophages, and thrombus. Media necrosis, fragmentation of the elastic laminae, and adventitial remodeling were more pronounced in Plg+/+ than in Plg-/- recipient mice. Expression of the plasminogen activators (PA), urokinase-type PA (u-PA) and tissue-type PA (t-PA), and expression of the matrix metalloproteinases (MMPs), MMP-3, MMP-9, MMP-12, and MMP-13, were significantly increased within 15 d of transplantation when cells actively migrate. These data indicate that plasmin proteolysis plays a major role in allograft arteriosclerosis by mediating elastin degradation, macrophage infiltration, media remodeling, medial smooth muscle cell migration, and formation of a neointima.

<p>The file Supplementary Information contains 9 Supplementary Figures and additional Materials and Methods mainly related to experiments done during the process of the Revision. Here is a short description of each Supplementary Figure: Supplementary Figure S1. Reduction of the DC101 dosage to 10 mg/kg results in a significant, additive treatment effect in the TS/A model when combined with ATRA. Supplementary Figure S2. Growth curves showing tumor kinetics up to 9 days after stopping the treatment with DC101 and ATRA. Supplementary Figure S3. ATRA decreases the DC101-induced expression of the alternative hypoxia marker GLUT1, whereas CD8+ T-cell and NK cell populations in TS/A breast cancer tumors remain unchanged upon treatment. Supplementary Figure S4. Characterization of the proangiogenic phenotype of tumor-infiltrating MDSC. Supplementary Figure S5. Characterization of the matricellular composition in 4T1 tumors. Supplementary Figure S6. In vitro generated MDSC efficiently suppress T cell proliferation. Supplementary Figure S7. (A) Intratumoral S100A8 levels show a strong correlation with FITC-lectin leakage. (B) ATRA has no direct influence on ZO-1 protein levels in vitro. Supplementary Figure S8. The therapeutic efficiency of DC101 is not increased in S100A9 knockout bone marrow transplanted mice, which exhibit tumor-dependent S100A8 recovery. Supplementary Figure S9. Analysis of the Vegf and Fgf expression levels of mast cells and cancer associated fibroblasts in 4T1 tumors. The Supplementary Materials and Methods section contains a description of: used Reagents and proteins, quantitative PCR, sequences of oligonucleotide primers used for quantitative PCR, fluorescence activated cell sorting (FACS) of mast cells and cancer assoicated fibroblasts, bone marrow transplantation, scanning electron microscopy, western blotting, ELISA, allogeneic T cell proliferation assay, metabolomic analysis of 4T1 tumor tissue.</p>

Mitotic spindle assembly is mediated by two processes: a centrosomal and a chromosomal pathway. RanGTP regulates the latter process by releasing microtubule-associated proteins from inhibitory complexes. NuSAP, a microtubule- and DNA-binding protein, is a target of RanGTP and promotes the formation of microtubules near chromosomes. However, the contribution of NuSAP to cell proliferation in vivo is unknown. Here, we demonstrate that the expression of NuSAP highly correlates with cell proliferation during embryogenesis and adult life, making it a reliable marker of proliferating cells. Additionally, we show that NuSAP deficiency in mice leads to early embryonic lethality. Spindle assembly in NuSAP-deficient cells is highly inefficient and chromosomes remain dispersed in the mitotic cytoplasm. As a result of sustained spindle checkpoint activity, the cells are unable to progress through mitosis, eventually leading to caspase activation and apoptotic cell death. Together, our findings demonstrate that NuSAP is essential for proliferation of embryonic cells and, simultaneously, they underscore the importance of chromatin-induced spindle assembly.

Schneider and colleagues say that the new model, published in PLoS Medicine, promises to increase our understanding of lymphedema and hopefully accelerate the development and testing of new treatments.

The TAM family of receptor protein tyrosine kinases comprises three known members, namely Tyro3, Axl, and Mer. These receptors are widely expressed in the nervous system, including by oligodendrocytes, the cell type responsible for myelinating the CNS. We examined the potential role of the TAM family and of their principle cognate ligand, Gas6 (growth arrest gene 6), in modulating the phenotype of the cuprizone model of demyelination. We found that the expression profiles of Axl , Mer , and Gas6 mRNA were increased in the corpus callosum in a temporal profile correlating with the increased migration and proliferation of microglia/macrophages in this model. In contrast, expression of Tyro3 decreased, correlating with the loss of oligodendrocytes. Gas6 both promoted in vitro survival of oligodendrocytes (39.3 ± 3.1 vs 11.8 ± 2.4%) and modulated markers of activation in purified cultures of microglia (tumor necrosis factor α mRNA expression was reduced ∼48%). In Gas6 −/− mice subjected to cuprizone-challenge, demyelination was greater than in control mice, within the rostral region of the corpus callosum, as assessed by luxol fast blue staining (myelination reduced by 36%) and by ultrastructural analysis. An increased loss of Gst-π (glutathione S -transferase-π)-positive oligodendrocytes was also identified throughout the corpus callosum of Gas6 −/− mice. Microglial marker expression (ionized calcium-binding adapter molecule 1) was increased in Gas6 −/− mice but was restricted to the rostral corpus callosum. Therefore, TAM receptor activation and regulation can independently influence both oligodendrocyte survival and the microglial response after CNS damage.