scholarly journals Fluid Shear Stress Enhances Differentiation of Jejunal Human Enteroids in Intestine-Chip

Author(s):  
Jianyi Yin ◽  
Laxmi Sunuwar ◽  
Magdalena Kasendra ◽  
Huimin Yu ◽  
Chung-Ming Tse ◽  
...  

Background and Aims: There is increasing evidence that study of normal human enteroids duplicates many known aspects of human intestinal physiology. However, this epithelial cell-only model lacks the many non-epithelial intestinal cells present in the gastrointestinal tract and exposure to the mechanical forces to which the intestine is exposed. We tested the hypothesis that physical shear forces produced by luminal and blood flow would provide an intestinal model more closely resembling normal human jejunum. Methods: Jejunal enteroid monolayers were studied in the Emulate, Inc Intestine-Chip under conditions of constant luminal and basolateral flow that was designed to mimic normal intestinal fluid flow, with human umbilical vein endothelial cells (HUVECs) on the basolateral surface and with Wnt3A, R-spondin, Noggin only on the luminal surface. Results: The jejunal enteroids formed monolayers that remained confluent for 6-8 days; began differentiating at least as early as day two post-plating, and demonstrated continuing differentiation over the entire time of the study as shown by quantitative real-time polymerase chain reaction and Western blotting. These results were consistent with continual differentiation, as was shown to occur in mouse villus enterocytes. Compared to differentiated enteroid monolayers grown on Transwell inserts, enteroids exposed to flow were more differentiated but exhibited increased apoptosis and reduced carbohydrate metabolism as shown by proteomic analysis. Conclusions: This study of human jejunal enteroids-on-chip suggests that luminal and basolateral flow produce a model of continual differentiation over time and NaCl absorption that mimics normal intestine and should provide new insights in intestinal physiology.

Blood ◽  
1993 ◽  
Vol 82 (9) ◽  
pp. 2684-2692
Author(s):  
KJ Faucette ◽  
LA Fitzgerald ◽  
L Liu ◽  
CJ Parker ◽  
GM Rodgers

Normal human plasma contains procoagulant albumin (PC-Al), an anionic form of albumin that induces tissue factor (TF) activity in human umbilical vein endothelial cells (HUVEC) and monocytes. In this study, we investigated both the interactions between HUVEC and PC-Al and the mechanism by which PC-Al induces TF activity. Binding of PC-Al to HUVEC was specific and reversible. Further studies indicated that membrane- bound PC-Al was not internalized by HUVEC. A potential receptor on HUVEC was suggested by studies in which the capacity of a variety of reagents to inhibit the activity of PC-Al was quantitated. Induction of TF activity by PC-Al was antagonized by dextran sulfate, heparin, fucoidan, and concanavalin A but not by ovalbumin, polyglutamic acid, or polyvinyl sulfate. This competition profile bears similarities to those reported for scavenger receptors that have been identified on both HUVEC and monocytes. Involvement of protein kinase C (PKC) in the PC-Al-induced enhancement of TF activity was suggested by experiments in which staurosporine, an inhibitor of PKC, suppressed the activity of PC-Al. The induction of TF activity by PC-Al was further characterized by using a quantitative polymerase chain reaction assay. Increased TF mRNA was first seen after 1 hour of incubation with PC-Al. Maximal observed expression occurred at 2 hours, but at 5 hours, expression had significantly decreased. Monocytes could also be induced to express TF mRNA after a 2-hour incubation with PC-Al. These results suggest that the functionally relevant binding of PC-Al to HUVEC may be mediated through interactions with a membrane constituent that has some of the properties of a scavenger receptor and that this interaction augments TF activity by enhancing transcription of TF mRNA, at least in part, by a mechanism that is dependent on activation of PKC.


eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Nicolas Baeyens ◽  
Stefania Nicoli ◽  
Brian G Coon ◽  
Tyler D Ross ◽  
Koen Van den Dries ◽  
...  

Vascular remodeling under conditions of growth or exercise, or during recovery from arterial restriction or blockage is essential for health, but mechanisms are poorly understood. It has been proposed that endothelial cells have a preferred level of fluid shear stress, or ‘set point’, that determines remodeling. We show that human umbilical vein endothelial cells respond optimally within a range of fluid shear stress that approximate physiological shear. Lymphatic endothelial cells, which experience much lower flow in vivo, show similar effects but at lower value of shear stress. VEGFR3 levels, a component of a junctional mechanosensory complex, mediate these differences. Experiments in mice and zebrafish demonstrate that changing levels of VEGFR3/Flt4 modulates aortic lumen diameter consistent with flow-dependent remodeling. These data provide direct evidence for a fluid shear stress set point, identify a mechanism for varying the set point, and demonstrate its relevance to vessel remodeling in vivo.


Blood ◽  
1993 ◽  
Vol 82 (9) ◽  
pp. 2684-2692 ◽  
Author(s):  
KJ Faucette ◽  
LA Fitzgerald ◽  
L Liu ◽  
CJ Parker ◽  
GM Rodgers

Abstract Normal human plasma contains procoagulant albumin (PC-Al), an anionic form of albumin that induces tissue factor (TF) activity in human umbilical vein endothelial cells (HUVEC) and monocytes. In this study, we investigated both the interactions between HUVEC and PC-Al and the mechanism by which PC-Al induces TF activity. Binding of PC-Al to HUVEC was specific and reversible. Further studies indicated that membrane- bound PC-Al was not internalized by HUVEC. A potential receptor on HUVEC was suggested by studies in which the capacity of a variety of reagents to inhibit the activity of PC-Al was quantitated. Induction of TF activity by PC-Al was antagonized by dextran sulfate, heparin, fucoidan, and concanavalin A but not by ovalbumin, polyglutamic acid, or polyvinyl sulfate. This competition profile bears similarities to those reported for scavenger receptors that have been identified on both HUVEC and monocytes. Involvement of protein kinase C (PKC) in the PC-Al-induced enhancement of TF activity was suggested by experiments in which staurosporine, an inhibitor of PKC, suppressed the activity of PC-Al. The induction of TF activity by PC-Al was further characterized by using a quantitative polymerase chain reaction assay. Increased TF mRNA was first seen after 1 hour of incubation with PC-Al. Maximal observed expression occurred at 2 hours, but at 5 hours, expression had significantly decreased. Monocytes could also be induced to express TF mRNA after a 2-hour incubation with PC-Al. These results suggest that the functionally relevant binding of PC-Al to HUVEC may be mediated through interactions with a membrane constituent that has some of the properties of a scavenger receptor and that this interaction augments TF activity by enhancing transcription of TF mRNA, at least in part, by a mechanism that is dependent on activation of PKC.


2012 ◽  
Vol 7 (1) ◽  
pp. 110-114 ◽  
Author(s):  
LIANG-LIANG SUN ◽  
LE ZHANG ◽  
XIANG-LAN MENG ◽  
FENG ZHANG ◽  
YUN ZHAO ◽  
...  

2013 ◽  
Vol 74 ◽  
pp. 36-40 ◽  
Author(s):  
Feng Zhang ◽  
Le Zhang ◽  
Liang-liang Sun ◽  
Xiang-lan Meng ◽  
Yun Zhao ◽  
...  

1996 ◽  
Vol 271 (3) ◽  
pp. C994-C1000 ◽  
Author(s):  
S. Li ◽  
R. S. Piotrowicz ◽  
E. G. Levin ◽  
Y. J. Shyy ◽  
S. Chien

The small molecular mass heat shock protein of 27 kDa (HSP27) has been shown to influence actin filament dynamics and endothelial cell behavior in ways similar to those observed during laminar flow. We have employed human umbilical vein endothelial cells to determine whether fluid shear stress affects HSP27 expression or phosphorylation. After a shear stress of 16 dyn/cm2, HSP27 became more highly phosphorylated, with maximum increase in phosphorylation levels (3-fold) attained by 30 min and sustained for at least 20 h. HSP27 antigen levels did not change; however, HSP27 mRNA levels decreased by 20% after 16 h. In bovine aortic endothelial cells stably transfected with the wild-type human HSP27 gene, shear stress induced the phosphorylation of both the exogenous human HSP27 and the endogenous bovine HSP25. The product of a transfected mutant HSP27 gene in which the putative phosphorylation sites Ser-15, Ser-78, and Ser-82 had been replaced with Gly was not phosphorylated. Thus the modulation of HSP27 and its activity by shear stress is mediated through a posttranslational mechanism and differs from the shear stress induction of immediate early genes at the level of transcription.


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