Cleft-like boundaries represent a type of cell sorting boundary characterized by the presence of a physical gap between tissues. We studied the cleft-like ectoderm-mesoderm boundary in Xenopus laevis and zebrafish gastrulae. We identified the transcription factor Snail1 as being essential for tissue separation, showed that its expression in the mesoderm depends on noncanonical Wnt signaling, an...

The present work investigated the mechanism for down-regulation of thrombomodulin (TM), an anticoagulant glycoprotein, on cultured umbilical vein endothelial cells (HUVECs) exposed to lipid extracts from oxidized low-density lipoprotein (oxLDL). HUVECs exposed to phospholipid extracts, but not to free cholesterol, triglyceride, or cholesterol ester, isolated from ox-LDL reduced TM mRNA levels t...

P pili are extracellular appendages responsible for the targeting of uropathogenic Escherichia coli to the kidney. They are assembled by the chaperone-usher (CU) pathway of pilus biogenesis involving two proteins, the periplasmic chaperone PapD and the outer membrane assembly platform, PapC. Many aspects of the structural biology of the Pap CU pathway have been elucidated, except for the C-term...

Assembly of P pili on the surface of pyelonephritic Escherichia coli proceeds from periplasmic chaperone-subunit complexes. The outer membrane protein PapC, which has been termed a molecular usher, is thought to be the site of assembly, where the chaperone dissociates from the subunits as they are incorporated into the pilus across the outer membrane. The kinetics of assembly and the energy req...

Protocadherins have been shown to regulate cell adhesion, cell migration, cell survival, and tissue morphogenesis in the embryo and the central nervous system, but little is known about the mechanism of protocadherin function. We previously showed that Xenopus paraxial protocadherin (PAPC) mediates cell sorting and morphogenesis by down-regulating the adhesion activity of a classical cadherin, ...

Ma, Zheng, Jiang Li, Lijuan Yang, Ying Mu, Wen Xie, Bruce Pitt, and Song Li. Inhibition of LPSand CpG DNA-induced TNFresponse by oxidized phospholipids. Am J Physiol Lung Cell Mol Physiol 286: L808–L816, 2004. First published November 26, 2003; 10.1152/ajplung.00220.2003.—Lipid oxidation is commonly seen in the innate immune response, in which reactive oxygen intermediates are generated to kill...

OBJECTIVE Previous studies have shown that oxidized products of PAPC (Ox-PAPC) regulate cell transcription of interleukin-8, LDL receptor, and tissue factor. This upregulation takes place in part through the activation of sterol regulatory element-binding protein (SREBP) and Erk 1/2. The present studies identify vascular endothelial growth factor receptor 2 (VEGFR2) as a major regulator in the ...

Oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine (ox-PAPC), a component of minimally modified low density lipoprotein, induces monocyte adhesion to endothelial cells. It is not known whether the upstroke slopes of pulsatile flow, defined as shear stress slew rates (tau(r)/tauT)), can regulate monocyte binding to ox-PAPC-treated bovine aortic endothelial cells (BAECs). At 60 cy...

BACKGROUND AND OBJECTIVES The Escherichia coli (E. coli) bacterium is one of the main causative agents of urinary tract infections (UTI) worldwide. The ability of this bacterium to form biofilms on medical devices such as catheters plays an important role in the development of UTI. The aim of the present study was to investigate the possible relationship between virulence factors and biofilm fo...

PapC ushers are outer-membrane proteins enabling assembly and secretion of P pili in uropathogenic E. coli. Their translocation domain is a large β-barrel occluded by a plug domain, which is displaced to allow the translocation of pilus subunits across the membrane. Previous studies suggested that this gating mechanism is controlled by a β-hairpin and an α-helix. To investigate the role of thes...