scholarly journals Chemically defined human vascular laminins for biologically relevant culture of hiPSC-derived brain microvascular endothelial cells

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Pedram Motallebnejad ◽  
Samira M. Azarin

Abstract Background In recent years, differentiation of human induced pluripotent stem cells (hiPSCs) into brain-specific microvascular endothelial cells (iBMECs) has frequently been used to model the blood–brain barrier (BBB). However, there are limitations in the use of iBMECs for in vitro studies, such as transendothelial electrical resistance (TEER) instability, weak junctional expression of VE-cadherin, and lack of proper fluid shear stress response. In vivo, the basement membrane (BM) composition of the BBB evolves throughout development, and laminins become the dominant component of the mature vascular BM. However, laminin isoforms of the endothelial BM have not been used for culture of differentiated iBMECs. The main goal of this study is to investigate the effect of different laminin isoforms of the endothelial BM on iBMEC functionality and to determine whether better recapitulation of the physiological BM in vitro can address the aforementioned limitations of iBMECs. Methods Using a previously reported method, hiPSCs were differentiated into iBMECs. The influence of main laminins of the endothelial BM, LN 411 and LN 511, on iBMEC functionality was studied and compared to a collagen IV and fibronectin mixture (CN IV-FN). Quantitative RT-PCR, immunocytochemistry, and TEER measurement were utilized to assess gene and protein expression and barrier properties of iBMECs on different extracellular matrices. Single-channel microfluidic devices were used to study the effect of shear stress on iBMECs. Results LN 511, but not LN 411, improved iBMEC barrier properties and resulted in more sustained TEER stability. Immunocytochemistry showed improved junctional protein expression compared to iBMECs cultured on CN IV-FN. iBMECs cultured on LN 511 showed a reduction of stress fibers, indicating resting endothelial phenotype, whereas gene expression analysis revealed upregulation of multiple genes involved in endothelial activation in iBMECs on CN IV-FN. Finally, culturing iBMECs on LN 511 enhanced physiological responses to shear stress, including morphological changes and enhanced junctional protein association. Conclusion LN 511 improves the functionality and long-term barrier stability of iBMECs. Our findings suggest that incorporation of physiologically relevant LN 511 in iBMEC culture would be beneficial for disease modeling applications and BBB-on-a-chip platforms that accommodate fluid flow.

2005 ◽  
Vol 288 (2) ◽  
pp. C272-C281 ◽  
Author(s):  
Hitoshi Ogawa ◽  
David G. Binion ◽  
Jan Heidemann ◽  
Monica Theriot ◽  
Pamela J. Fisher ◽  
...  

Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is a homing receptor preferentially expressed on gut-associated endothelial cells that plays a central role in leukocyte traffic into the mucosal immune compartment. Although the molecular mechanisms underlying endothelial ICAM-1 or E-selectin expression have been intensively investigated, the mechanisms that regulate human MAdCAM-1 expression have not been defined. We report MAdCAM-1 gene and protein expression in primary cultures of human intestinal microvascular endothelial cells (HIMEC) that was not demonstrated in human umbilical vein endothelial cells. Similar to ICAM-1 and E-selectin expression, MAdCAM-1 gene expression in HIMEC was inducible with TNF-α, IL-1β, or LPS activation. However, in striking contrast to ICAM-1 and E-selectin expression, MAdCAM-1 mRNA and protein expression in HIMEC was heavily dependent on culture duration and/or cellular density, suggesting a prominent role for cell-cell interaction among these endothelial cells in the expression of the mucosal addressin. MAdCAM-1 expression was inhibited by both SN-50 (NF-κB inhibitor) and LY-294002 [phosphatidylinositol 3-kinase (PI3-K) inhibitor], whereas ICAM-1 and E-selectin expression was inhibited by SN-50 but not by LY-294002. The Akt phosphorylation by TNF-α or LPS was greater at higher cell density, demonstrating a pattern similar to that of MAdCAM-1 expression. NF-κB activation was not affected by cellular density in HIMEC. MAdCAM-1 expression in human gut endothelial cells is regulated by distinct signaling mechanisms involving both NF-κB and PI3-K/Akt. These data also suggest that PI3-K/Akt is involved in the gut-specific differentiation of HIMEC, which results in expression of the mucosal addressin MAdCAM-1.


Blood ◽  
2006 ◽  
Vol 109 (4) ◽  
pp. 1515-1523 ◽  
Author(s):  
Li Song ◽  
Shujun Ge ◽  
Joel S. Pachter

Abstract Recent evidence from this laboratory indicated that reduced expression of caveolin-1 accompanied the diminished expression of tight junction (TJ)–associated proteins occludin and zonula occludens-1 (ZO-1) following stimulation of brain microvascular endothelial cells (BMECs) with the chemokine CCL2 (formerly called MCP-1). Because attenuated caveolin-1 levels have also been correlated with heightened permeability of other endothelia, the objective of this study was to test the hypothesis that reduced caveolin-1 expression is causally linked to the action of CCL2 on BMEC junctional protein expression and barrier integrity. This was achieved using adenovirus to nondestructively deliver caveolin-1 siRNA (Ad-siCav-1) to BMEC monolayers, which model the blood-brain barrier (BBB). Treatment with siRNA reduced the caveolin-1 protein level as well as occludin and ZO-1. Additionally, occludin exhibited dissociation from the cytoskeletal framework. These changes were attended by comparable alterations in adherens junction (AJ)–associated proteins, VE-cadherin and β-catenin, increased BMEC paracellular permeability, and facilitated the ability of CCL2 to stimulate monocytic transendothelial migration. Furthermore, treating BMECs with cavtratin, a synthetic cell-permeable peptide encoding the caveolin-1 scaffolding domain, antagonized effects of both Ad-siCav-1 and CCL2. These results collectively highlight caveolin-1 loss as a critical step in CCL2-induced modulation of BMEC junctional protein expression and integrity, and possibly serve a crucial role in regulating inflammation at the BBB.


Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Sina Salehi Omran ◽  
Fernando Garcia Polite ◽  
Elazer Edelman ◽  
Mercedes Balcells-Camps

Introduction: Dementia has classically been identified to be of either vascular or neural origin. These domains overlap and are complementary, thus we consider dementia a disease of the single cerebrovascular unit. Our objective was to generate a modular platform for co-culture of brain microvascular endothelial cells and astrocytes that also incorporates mechanical stresses, and to then use this model of the cerebrovascular unit microenvironment to study the unit in vitro . Hypothesis: We assessed the hypothesis that endothelial health and blood-brain barrier integrity are modulated by shear stress and co-culture with astrocytes. Methods: We lithographed polydimethylsiloxane substrate on Teflon negative molds with subjacent rectangular channels of 0.45 and 2 mm depth for seeding of human brain microvascular cells and astrocytes, respectively, separated by a polytetrafluoroethylene (0.45 μm pore size) membrane under no flow or physiologic flow (6.2 dynes/cm 2 ) for one week. Immunocytochemical staining for glial fibrillary acidic protein and CD31 was simultaneously visualized by confocal microscopy. Cells from each channel were detached via trypsinization, and expression of transport proteins P-glycoprotein (P-gp) and glucose transporter-1 (GLUT-1), in addition to junction proteins zona occludens-1 (ZO-1) and CD31, was measured by Western Blot. Results: We stably co-cultured brain microvascular endothelial cells and astrocytes with no chamber leakage or mixing. CD31 staining revealed endothelial cell alignment to direction of flow. Expression of ZO-1 by endothelial cells increased in presence of flow and co-culture independently, by 1.6-fold in combined conditions relative to static monoculture (p<0.05). For P-gp, the increase in combined conditions was 5.5-fold (p<0.05). GLUT-1 and CD31 levels did not change significantly with co-culture or flow. Conclusion: Cell biology devoid of microenvironmental cues provides limited insight, especially when considering whole tissues, on the impact of disease. A co-culture system that introduces multiple cells, flow, controlled stress and independent visualization and sampling of each cell domain adds deeper understanding and greater value to in vitro biological models and tissue biology.


PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249814
Author(s):  
Leah A. Marquez-Curtis ◽  
Reid Bokenfohr ◽  
Locksley E. McGann ◽  
Janet A. W. Elliott

The blood–brain barrier (BBB) keeps pathogens and toxins out of the brain but also impedes the entry of pharmaceuticals. Human cerebral microvascular endothelial cells (hCMECs) and astrocytes are the main functional cell components of the BBB. Although available commercially as cryopreserved cells in suspension, improvements in their cryopreservation and distribution as cryopreserved monolayers could enhance BBB in vitro studies. Here, we examined the response to slow cooling and storage in liquid nitrogen of immortalized hCMEC/D3 cells and human primary astrocytes in suspension and in monolayers. HCMEC/D3 cells in suspension cryopreserved in 5% dimethyl sulfoxide (DMSO) and 95% fetal bovine serum or in 5% DMSO and 6% hydroxyethyl starch (HES) showed post-thaw membrane integrities above 90%, similar to unfrozen control. Cryopreservation did not affect the time-dependent ability of hCMEC/D3 cells to form tubes on Matrigel. Primary astrocytes in suspension cryopreserved in the presence of 5% DMSO and 6% HES had improved viability over those cryopreserved in 10% DMSO. Monolayers of single cultures or co-cultures of hCMEC/D3 cells and astrocytes on fibronectin-coated Rinzl coverslips retained membrane integrities and metabolic function, after freezing in 5% DMSO, 6% HES, and 2% chondroitin sulfate, that were comparable to those of unfrozen controls even after overnight incubation. Rinzl is better than glass or Thermanox as an underlying solid substrate for cryopreserving hCMEC/D3 monolayers. Cryopreserved hCMEC/D3 monolayers expressed the junction proteins ZO-1 and claudin-5 similar to their unfrozen counterparts. Hence, we describe improved cryopreservation protocols for hCMEC/D3 cells and astrocytes in suspension, and a novel protocol for the cryopreservation of monolayers of hCMEC/D3 cells and astrocytes as single cultures or co-cultures that could expand their distribution for research on disease modeling, drug screening, and targeted therapy pertaining to the BBB.


1996 ◽  
Vol 36 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Nobuhiro Ichikawa ◽  
Kohji Naora ◽  
Hidenari Hirano ◽  
Michio Hashimoto ◽  
Sumio Masumura ◽  
...  

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