Niches containing stem/progenitor cells are present in different anatomical locations along the human biliary tree and within liver acini. The most primitive stem/progenitors, biliary tree stem/progenitor cells (BTSCs), reside within peribiliary glands located throughout large extrahepatic and intrahepatic bile ducts. BTSCs are multipotent and can differentiate towards hepatic and pancreatic ce...

Primary cilia, thin hair-like structures protruding from the apical surface of most mammalian cells, have gained the attention of many researchers over the past decade. Primary cilia are microtubule-filled sensory organelles that are enclosed within the ciliary membrane. They originate at the cell surface from the mother centriole that becomes the mature basal body. In this review, we will disc...

Cell cultures derived from trabecular meshworks of human and bovine eyes and from bovine vascular endothelia were incubated at 37 degrees C for 1 hr with ethacrynic acid (ECA, 0.1-0.5 mmol/l) dissolved in culture medium. At 2 hr after the initial exposure, ECA at concentrations up to 0.4 mmol/l induced a reversible alteration in cell shape in all three cell types that was coincident with a chan...

New evidence confirms the multi-step model for leukocyte migration through endothelia, but with a twist. The selectins are not always required, and some lymphocyte subsets rely heavily on integrins for their migration to tissues.

METHODS. The endothelia of 505 of the 559 corneas consecutively stored at the eye bank were routinely analyzed with Sambacornea image-analysis software (ver. 1.2.10; Tribvn, Châtillon, France) on three large-field images of 75

A recent paper in BMC Biology reports that actin stress fibers in adjacent cultured endothelial cells are linked through adherens junctions. This organization might provide a super-cellular network that could enable coordinated signaling and structural responses in endothelia.

Enabled/vasodilator-stimulated phosphoprotein (Ena/VASP) proteins are key actin regulators that localize at regions of dynamic actin remodeling, including cellular protrusions and cell-cell and cell-matrix junctions. Several studies have suggested that Ena/VASP proteins are involved in the formation and function of cellular junctions. Here, we establish the importance of Ena/VASP in endothelial...

Freshly cultured vascular endothelial cells express the CD34 antigen in a diffuse cell surface pattern with some concentration on microvilli. Expression is downregulated with proliferation in continuous culture and undetectable after nine population doublings but can be maintained by restraining cell proliferation and promoting cell contact. Expression of CD34 at the antigen and mRNA levels on ...

Neovascularization depends on vascular cell proliferation and on the stabilization of vessels by association of vascular smooth muscle–like pericytes with ECs. Here we show that integrin α4β1 (VLA-4) and VCAM-1 promote close intercellular adhesion between ECs and pericytes and that this interaction is required for blood vessel formation. Integrin α4β1 is expressed by proliferating but not quies...

Increased expression of Notch signaling pathway components is observed in Kaposi sarcoma (KS) but the mechanism underlying the manipulation of the canonical Notch pathway by the causative agent of KS, Kaposi sarcoma herpesvirus (KSHV), has not been fully elucidated. Here, we describe the mechanism through which KSHV directly modulates the expression of the Notch ligands JAG1 and DLL4 in lymphat...