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The bloodDSbrain barrier (BBB) represents the interface between the brain and other body tissues. Its ability to protect the brain from harmful compounds has attracted the attention of clinicians and investigators, but far from being a simple physical barrier, the BBB is a complex, heterogeneous, and dynamic tissue. The integrated function of the cerebral microvasculature, tight junction proteins, brain microvascular endothelial cells (BMECs), cellular transport pathways, and enzymatic machinery jointly contribute to normal BBB integrity. Aging, systemic diseases, and ischemic injury can disrupt these processes, resulting in a decline in overall BBB function and integrity. Based on the published literature, this study proposes that age- and disease-related BBB alterations play a key role in diminishing the ability of older patients to recover from acute ischemic stroke. Evidence linking deficits in the cerebral microvasculature and BBB integrity to dementia, medication-related cognitive decline, white matter disease (WMD or leukoaraiosis), and related geriatric syndromes including delirium, gait disorders, and urinary incontinence is also reviewed. Priority areas for a future research agenda include strategies to improve clinicians' ability to diagnose, prevent, and manage BBB abnormalities. In future years, in vivo measures such as functional and contrast-enhanced neuroimaging will be used to evaluate BBB integrity in older adults while also assessing the effectiveness of interventions, some targeting inflammatory pathways known to disrupt the BBB, for their ability to prevent or slow the progression of these complex multifactorial geriatric syndromes. [ABSTRACT FROM AUTHOR]

Abstract Background There is increasing awareness that, aside from producing cerebrospinal fluid, the choroid plexus (CP) might be a key regulator of immune activity in the central nervous system (CNS) during neuroinflammation. Specifically, the CP has recently been posited to control entry of sentinel T cells into the uninflamed CNS during the early stages of neuroinflammatory diseases, like multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). As the CP is compartmentalized into a stromal core containing fenestrated capillaries devoid of typical blood–brain barrier properties, surrounded by a tight junction-expressing choroidal epithelium, each of these compartments might mount unique responses that instigate the neuroinflammatory process. Methods To discern responses of the respective CP stromal capillary and choroidal epithelial tissues during evolving neuroinflammation, we investigated morphology and in situ expression of 93 immune-related genes during early stages of EAE induced by immunization with myelin oligodendrocyte glycoprotein peptide (MOG35-55). Specifically, 3-D immunofluorescent imaging was employed to gauge morphological changes, and laser capture microdissection was coupled to an Immune Panel TaqMan Low Density Array to detail alterations in gene expression patterns at these separate CP sites on days 9 and 15 post-immunization (p.i.). To resolve CP effects due to autoimmunity against MOG peptide, from those due to complete Freund’s adjuvant (CFA) and pertussis toxin (PTX) included in the immunization, analysis was performed on MOG-CFA/PTX-treated, CFA/PTX-treated, and naïve cohorts. Results The CP became swollen and displayed significant molecular changes in response to MOG-CFA/PTX immunization. Both stromal capillary and choroidal epithelial tissues mounted vigorous, yet different, changes in expression of numerous genes over the time course analyzed - including those encoding adhesion molecules, cytokines, chemokines, statins, interleukins, T cell activation markers, costimulatory molecules, cyclooxygenase, pro-inflammatory transcription factors and pro-apoptotic markers. Moreover, CFA/PTX-treatment, alone, resulted in extensive, though less robust, alterations in both CP compartments. Conclusions MOG-CFA/PTX immunization significantly affects CP morphology and stimulates distinct expression patterns of immune-related genes in CP stromal capillary and epithelial tissues during evolving EAE. CFA/PTX treatment, alone, causes widespread gene alterations that could prime the CP to unlock the CNS to T cell infiltration during neuroinflammatory disease.

Abstract Background Production of the chemokine CCL2 by cells of the neurovascular unit (NVU) drives critical aspects of neuroinflammation. Suppression of CCL2 therefore holds promise in treating neuroinflammatory disease. Accordingly, we sought to determine if the compound bindarit, which inhibits CCL2 synthesis, could repress the three NVU sources of CCL2 most commonly reported in neuroinflammation – astrocytes, microglia and brain microvascular endothelial cells (BMEC) – as well as modify the clinical course of neuroinflammatory disease. Methods The effect of bindarit on CCL2 expression by cultured murine astrocytes, microglia and BMEC was examined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Bindarit action on mouse brain and spinal cord in vivo was similarly investigated by qRT-PCR following LPS injection in mice. And to further gauge the potential remedial effects of bindarit on neuroinflammatory disease, its impact on the clinical course of experimental autoimmune encephalomyelitis (EAE) in mice was also explored. Results Bindarit repressed CCL2 expression by all three cultured cells, and antagonized upregulated expression of CCL2 in both brain and spinal cord in vivo following LPS administration. Bindarit also significantly modified the course and severity of clinical EAE, diminished the incidence and onset of disease, and evidenced signs of disease reversal. Conclusion Bindarit was effective in suppressing CCL2 expression by cultured NVU cells as well as brain and spinal cord tissue in vivo. It further modulated the course of clinical EAE in both preventative and therapeutic ways. Collectively, these results suggest that bindarit might prove an effective treatment for neuroinflammatory disease.

Focal adhesion kinase (FAK) is a cytoplasmic tyrosine kinase that mediates signal transduction by integrins as well as growth factor receptors. FAK has been implicated in multiple steps of carcinogenesis including tumor initiation, growth and metastasis. Amplification and overexpression of FAK have been observed in aggressive human cancers including breast cancer. We have now observed that VS-4718, a selective FAK kinase inhibitor, exhibits preferential inhibitory effects on breast cancer stem cells. VS-4718 is a potent and selective FAK kinase inhibitor that blocks fibronectin-stimulated FAK autophosphorylation at Tyr397 at low nanomolar concentrations. To determine if FAK plays a role in the biology of breast cancer stem cells, VS-4718 was evaluated in a multitude of cancer stem cell assays both in vitro and in vivo. In parallel, treatment of SUM159 triple negative breast cancer cells in vitro with FAK shRNA inhibits tumorsphere formation. These data taken together indicate a role of FAK in breast cancer stem cell renewal. Similarly, pre-treatment of SUM159 cells with VS-4718 in matrigel attenuated secondary tumorsphere formation. Furthermore, VS-4718 reduced the side population (SP) and the percentage of ALDEFLUOR+ cancer stem cells in SUM159 breast cancer cells in vitro. In direct contrast, standard-of-care agent paclitaxel increased the percentage of ALDEFLUOR+ cancer stem cells in all three assays. The in vivo effect of VS-4718 on cancer stem cells was evaluated in SUM159 and MDA-MB -231 human triple negative breast cancer xenograft models. Following systemic administration, VS-4718 induced significant reduction of cancer stem cells in tumors as assessed by a decrease in ALDEFLUOR+ cells and tumorsphere-forming efficiency relative to vehicle-treated tumors. In summary, our results indicate the importance of FAK in the self-renewal of breast cancer stem cells in vitro and in vivo, and support the clinical development of the selective FAK inhibitor VS-4718 to target cancer stem cells for the treatment of triple negative breast cancer. [ABSTRACT FROM AUTHOR]

Cancer stem cells (CSCs) support tumor viability and growth through their ability to self-renew and differentiate into heterogeneous tumor tissue. CSCs are typically resistant to standard cytotoxic agents, leading to their enrichment and the consequent regrowth of refractory tumors. While this population has been challenging to directly target therapeutically, we are actively developing novel agents, such as VS-507, that selectively target the cancer stem cell subpopulation in vivo. Previously, we and others have shown that VS-507, a cancer stem-cell specific agent, inhibits Wnt signaling with corresponding reduction of the LRP6 protein, a Frizzled co-receptor upregulated in breast cancer cell lines. In the current study, we have continued to examine the effect of VS-507 on the Wnt/Beta-catenin signaling pathway to further elucidate its mechanism of action. We determined that VS-507 also decreases expression of the second Frizzled co-receptor LRP5 in MDA-MB-231 breast cancer cells stimulated by Wnt3A. The combined inhibition of the co-receptors LRP5 and LRP6 may contribute to the observed inhibition of Beta-catenin-mediated transcription by VS-507 in a TOP-Flash assay. Accordingly, VS-507 reduced expression of Axin2, a transcriptional target of Beta-catenin. Because human breast cancer cell lines represent a mixed population of CSC and non-CSC cells, we evaluated VS-507 across a panel of cell lines by monitoring changes in viability and in the percentage of cancer stem cells. In SUM159 triple negative breast cancer cells, VS-507 had micromolar potency against the bulk population with preferential nanomolar potency against the ALDEFLUOR+ CSC population with similar effects observed in the Hoechst side population (SP) CSC assay. In contrast, cytotoxic anticancer drugs such as paclitaxel and cisplatin increased the percentage of ALDEFLUOR+ cancer stem cells under similar conditions. In vivo, oral administration of VS-507 (15 mg/kg, QD daily) as a single agent partially inhibited MDA-MB-231 tumor growth, consistent with its observed inhibition of the cancer stem cell subpopulation. Furthermore, VS-507 inhibited lung metastasis in a 4T1.2 murine breast cancer model. In summary, these results further elucidate the mechanism by which VS-507 inhibits Wnt/Beta-catenin signaling. VS-507 reduces tumor cell proliferation in vitro with preferential effects on cancer stem cells which translate to inhibition of tumor growth, enhancement of efficacy of cytotoxic agents such as docetaxel, and inhibition of metastasis in mouse models. These data provide additional support for the development of VS-507 as a novel anti-cancer stem cell agent. [ABSTRACT FROM AUTHOR]