Recombinant human uteroglobin/CC10 inhibits the adhesion and migration of primary human endothelial cells via specific and saturable binding to fibronectin

Abstract

Uteroglobin (UG) or Clara Cell 10 kDa protein (CC10) is a small, stable, epithelial secretory anti-inflammatory protein. Uteroglobin has been shown to inhibit neointimal formation in vivo after balloon angioplasty through an unknown mechanism. An interaction between UG and plasma fibronectin (Fn) has been demonstrated in mice. Since Fn plays a key role in endothelial cell (EC) migration and angiogenesis, we investigated whether recombinant human UG (rhUG) affects EC migration via Fn binding. In this report, we show a saturable binding of rhUG to Fn depending on Fn conformation and that rhUG is covalently cross-linked to Fn by transglutaminase (TGase). Additionally, our study highlights that rhUG can also bind to exogenously added or self-secreted Fn on the membrane of human primary microvascular endothelial cells (HMVEC), although these complexes are weakly associated with the plasmalemma. Upon the interaction with Fn in solid phase, rhUG strongly inhibits HMVEC attachment on Fn, but not on other ECM proteins. Consequently, rhUG also inhibits cell migration in a dose dependent fashion (I.C.50 = 65 nM) and hinders the "wound healing" in vitro. The small size, stability and human tolerability of rhUG suggest that rhUG in slow-release form or genetically delivered could be used in humans to modulate cell/Fn interactions in the context of tumor microenvironment or in the context of inflammation and fibrosis.

Selective control of endothelial cell proliferation with a synthetic dimerizer of FGF receptor-1

“…Attempts to induce HMVEC migration failed due to extensive cell death under the low serum conditions required to test the effects of bFGF or dimerizer. A less stringent serum starvation protocol as described by Antico et al 37 for HMVEC migration did not ameliorate the problem in our hands. We also attempted to test if dimerization of FGFR4 would stimulate HUVECs to migrate and proliferate as effectively as bFGF treatment.…”

Delineating the signals by which repetitive deformation stimulates intestinal epithelial migration across fibronectin

“…Such apparently small changes may very well be important in an intricately and tightly regulated biological system that is experiencing constant injury to the mucosal layer. We (7,11) and others (4,19,34,67) have studied changes in cell migration, proliferation, or cell signaling in intestinal epithelial cells of similar magnitudes in response to other stimuli. Such differences in the speed of gut epithelial restitution could be enough to determine whether a mucosal wound heals or whether the mucosal barrier breaks down in vivo.…”

DC-LAMP stains pulmonary adenocarcinoma with bronchiolar Clara cell differentiation

“…There was no detectable labeling in any other adenocarcinomas, mesenchymal tumors, and melanomas. The protein CC-10 is homologous to human uteroglobin, a protein that is expressed in endometrial cells [27]. The reasons for the colocalization of CC-10 and DC-LAMP in endometrial adenocarcinomas is not clear.…”

“…In addition, DC-LAMP is located on chromosome 3q27 [8,10,11], whereas CC-10 is localized on chromosome 11q13 [28], which suggests that these two molecules are not regulated under the same promoter. DC-LAMP seems to colocalize with lysosomes, and CC-10 is a protein secreted by Clara cells and thought to have anti-inflammatory properties [7,27]. CC-10 expression by endometrial cells seems to be hormonal, regulated with higher expressions during the progesterone phase of the menstrual cycle [29].…”