Fzd7 (Frizzled-7) Expressed by Endothelial Cells Controls Blood Vessel Formation Through Wnt/β-Catenin Canonical Signaling.

Objective: Vessel formation requires precise orchestration of a series of morphometric and molecular events controlled by a multitude of angiogenic factors and morphogens. Wnt/frizzled signaling is required for proper vascular formation. In this study, we investigated the role of the Fzd7 (frizzled-7) receptor in retinal vascular development and its relationship with the Wnt/β-catenin canonical pathway and Notch signaling.

Frizzled7 controls vascular permeability through the Wnt-canonical pathway and cross-talk with endothelial cell junction complexes.

Aims: Vascular permeability is essential for the health of normal tissues and is an important characteristic of many disease states. The role of the Wnt/frizzled pathway in vascular biology has recently been reported. The objectives of this study are to analyse the role of Frizzled7 (Fzd7) receptor in the control of vascular integrity.

Frizzled 4 regulates arterial network organization through noncanonical Wnt/planar cell polarity signaling.

Rationale: A growing body of evidence supports the hypothesis that the Wnt/planar cell polarity (PCP) pathway regulates endothelial cell proliferation and angiogenesis, but the components that mediate this regulation remain elusive.

Objective: We investigated the involvement of one of the receptors, Frizzled4 (Fzd4), in this process because its role has been implicated in retinal vascular development.

Methods And Results: We found that loss of fzd4 function in mice results in a striking reduction and impairment of the distal small artery network in the heart and kidney.

Effects of human follicular fluid and high-density lipoproteins on early spermatozoa hyperactivation and cholesterol efflux.

The preovulatory human follicular fluid contains only HDLs as a lipoprotein class with a typically high proportion of prebeta HDL. We first examined the role of follicular fluid and HDL subfractions on human spermatozoa capacitation, a process characterized by a hyperactivation of the flagellar movement and a depletion of plasma membrane cholesterol. Whole follicular fluid and isolated HDL, used at constant free cholesterol concentration, were both able to promote an early flagellar hyperactivation.

FrzA/sFRP-1, a secreted antagonist of the Wnt-Frizzled pathway, controls vascular cell proliferation in vitro and in vivo.

Objective: FrzA, a member of the group of secreted frizzled related proteins (sFRP) that is expressed in the cardiovascular system, has been shown to antagonize the Wnt/frizzled signaling pathway. We have recently demonstrated its role in vascular cell growth control in vitro. In this study, we aimed to examine the mechanisms by which FrzA exerts its antiproliferative effect on vascular cells in vitro and its potential effect in vivo.