Characterization of the GM1 oligosaccharide transport across the blood-brain-barrier

Ganglioside GM1 has demonstrated to attenuate Parkinson Disease (PD) symptoms in clinical and preclinical trials. Nevertheless, the GM1 efficacy revealed in vitro is critically reduced in vivo, because of the amphiphilic behavior that limits the passage across the blood brain barrier (BBB). In vitro and in vivo experiments showed that GM1 exerts neurotrophic functions by interacting with plasma membrane (PM) proteins throughout its oligosaccharide portion (OligoGM1). Furthermore, OligoGM1 intravenously or subcutaneously injected into mice is absorbed and taken up by different organs and tissues, including brain. In order to take advantage of GM1 oligosaccharide properties and to overcome GM1 pharmacological limitation, this study has been aimed by the investigation of the OligoGM1 transportthrough the BBB, by using a human in vitro model for human brain-like endothelial cells (hBLEC). Ruled out the toxicity of OligoGM1 on hBLEC, the OligoGM1 transport across the hBBB has been analyzed, finding out a 20 fold higher rate than GM1 and a time and concentration dependence. In order to characterize the OligoGM1 passage, a direct evaluation of the OligoGM1 interaction with the ABC-transporters was carried on, leaving out this way for OligoGM1 transport. Moreover, inverse- and 4\ub0C-transport experiments were performed excluding the implication of the active transport for OligoGM1 passage across the hBLEC, leading to consider the passive-paracellular route. Furthermore, after the hBLEC transport, OligoGM1 maintained its stability and capacity to induce neuritogenesis in the mouse neuroblastoma cells line Neuro2a. This preliminary study has improved the knowledge about the GM1 pharmacological potential by proving that OligoGM1 can cross advantageously the BBB, offering a new promising therapeutic strategy

Advancing human induced pluripotent stem cell-derived blood-brain barrier models for studying immune cell interactions.

Human induced pluripotent stem cell (hiPSC)-derived blood-brain barrier (BBB) models established to date lack expression of key adhesion molecules involved in immune cell migration across the BBB in vivo. Here, we introduce the extended endothelial cell culture method (EECM), which differentiates hiPSC-derived endothelial progenitor cells to brain microvascular endothelial cell (BMEC)-like cells with good barrier properties and mature tight junctions. Importantly, EECM-BMEC-like cells exhibited constitutive cell surface expression of ICAM-1, ICAM-2, and E-selectin. Pro-inflammatory cytokine stimulation increased the cell surface expression of ICAM-1 and induced cell surface expression of P-selectin and VCAM-1. Co-culture of EECM-BMEC-like cells with hiPSC-derived smooth muscle-like cells or their conditioned medium further increased the induction of VCAM-1. Functional expression of endothelial ICAM-1 and VCAM-1 was confirmed by T-cell interaction with EECM-BMEC-like cells. Taken together, we introduce the first hiPSC-derived BBB model that displays an adhesion molecule phenotype that is suitable for the study of immune cell interactions

A three-scale domain decomposition method for the 3D analysis of debonding in laminates

The prediction of the quasi-static response of industrial laminate structures requires to use fine descriptions of the material, especially when debonding is involved. Even when modeled at the mesoscale, the computation of these structures results in very large numerical problems. In this paper, the exact mesoscale solution is sought using parallel iterative solvers. The LaTIn-based mixed domain decomposition method makes it very easy to handle the complex description of the structure; moreover the provided multiscale features enable us to deal with numerical difficulties at their natural scale; we present the various enhancements we developed to ensure the scalability of the method. An extension of the method designed to handle instabilities is also presented

Early carboniferous brachiopod faunas from the Baoshan block, west Yunnan, southwest China

38 brachiopod species in 27 genera and subgenera are described from the Yudong Formation in the Shidian-Baoshan area, west Yunnan, southwest China. New taxa include two new subgenera: Unispirifer (Septimispirifer) and Brachythyrina (Longathyrina), and seven new species: Eomarginifera yunnanensis, Marginatia cylindrica, Unispirifer (Unispirifer) xiangshanensis, Unispirifer (Septimispirifer) wafangjieensis, Brachythyrina (Brachythyrina) transversa, Brachythyrina (Longathyrina) baoshanensis, and Girtyella wafangjieensis. Based on the described material and constraints from associated coral and conodont faunas, the age of the brachiopod fauna from the Yudon Formation is considered late Tournaisian (Early Carboniferous), with a possibility extending into earlyViseacutean.<br /

A novel dynamic multicellular co-culture system for studying individual blood-brain barrier cell types in brain diseases and cytotoxicity testing

Blood brain barrier (BBB) cells play key roles in the physiology and pathology of the central nervous system (CNS). BBB dysfunction is implicated in many neurodegenerative diseases, including Alzheimer’s disease (AD). The BBB consists of capillary endothelial cells, pericytes encircling the endothelium and surrounding astrocytes extending their processes towards it. Although there have been many attempts to develop in vitro BBB models, the complex interaction between these celltypes makes it extremely difficult to determine their individual contribution to neurotoxicity in vivo. Thus, we developed and optimised an in vitro multicellular co-culture model within the Kirkstall Quasi Vivo System. The main aim was to determine the optimal environment to culture human brain primary endothelial cells, pericytes and astrocytes whilst maintaining cellular communication without formation of a barrier in order to assess the contribution of each cell type to the overall response. As a proof of concept for the present system, the effects of amyloid-beta 25-35 peptide (Aβ25-35), a hall mark of AD, were explored. This multicellular system will be a valuable tool for future studies on the specific roles of individual BBB cell type (while making connection with each other through medium) in CNS disorders as well as in cytotoxicity tests

Abstracts from the 20th International Symposium on Signal Transduction at the Blood-Brain Barriers

https://deepblue.lib.umich.edu/bitstream/2027.42/138963/1/12987_2017_Article_71.pd

Receptor-mediated PLGA nanoparticles for glioblastoma multiforme treatment

International audienceGlioblastoma multiforme is the most lethal type of brain tumor and the established therapy only extends patients survival to approximately one year. Its first-line treatment is based on of chemotherapy with the alkylating agent temozolomide (TMZ). As many other chemotherapeutic drugs, TMZ presents several limitations as high toxicity and low bioavailability. The delivery of TMZ using poly(lactic-co-glycolic acid) nanoparticles is proposed in this work. Stable nanoparticles functionalized with a OX26 type monoclonal antibody for transferrin receptor were developed, targeting the glioblastoma tumor cells, since these cells are known for overexpressing this receptor. The release profile of TMZ from the nanoparticles was studied mimicking physiological conditions, and targeted cellular internalization was also investigated. Two glioblastoma cell lines - U215 and U87 - were used to evaluate the in vitro cytotoxicity of the drug, showing that the prepared nanocarriers enhance the anticancer activity of TMZ. The functionalization with the monoclonal antibody for transferrin receptor proved to be advantageous in enhancing the cellular internalization in glioblastoma cells

Discovery of pyrazolo-thieno[3,2-d]pyrimidinylamino-phenyl acetamides as type-II pan-tropomyosin receptor kinase (TRK) inhibitors: Design, synthesis, and biological evaluation

Tropomyosin receptor kinase (TRK) represents an attractive oncology target for cancer therapy related to its critical role in cancer formation and progression. NTRK fusions are found to occur in 3.3% of lung cancers, 2.2% of colorectal cancers, 16.7% of thyroid cancers, 2.5% of glioblastomas, and 7.1% of pediatric gliomas. In this paper, we described the discovery of the type-II pan-TRK inhibitor 4c through the structure-based drug design strategy from the original hits 1b and 2b. Compound 4c exhibited excellent in vitro TRKA, TRKB, and TRKC kinase inhibitory activity and anti-proliferative activity against human colorectal carcinoma derived cell line KM12. In the NCI-60 human cancer cell lines screen, compound 4g demonstrated nearly 80% of growth inhibition for KM12, while only minimal inhibitory activity was observed for the remaining 59 cancer cell lines. Western blot analysis demonstrated that 4c and its urea cousin 4k suppressed the TPM3-TRKA autophosphorylation at the concentrations of 100 nM and 10 nM, respectively. The work presented that 2-(4-(thieno[3,2-d]pyrimidin-4-ylamino)phenyl)acetamides could serve as a novel scaffold for the discovery and development of type-II pan-TRK inhibitors for the treatment of TRK driven cancers