Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0021933 (intussusception)
 3,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CXC chemokine ligand 12 (CXCL12; stromal cell-derived factor-1 [SDF-1]/pre-B-cell growth-stimulating factor [PBSF]) and its receptor CXCR4 are essential for vascularization in the gastrointestinal tract as well as B lymphopoiesis and colonization of bone marrow by hematopoietic cells. However, the mechanism by which CXCL12/CXCR4 functions in blood vessel formation remains elusive. Here, we have found a novel mode of organ vascularization and determined the roles of CXCL12 in these processes. In the developing small intestine, many short interconnecting vessels form between larger superior mesenteric artery (SMA) and the neighboring primary capillary plexus surrounding the primitive gut, and they elongate and become the arteries supplying the small intestine. Mice lacking CXCL12 or CXCR4 lack the interconnecting vessels but have normal venous networks. The mutants lack filopodial extension and intussusception from endothelial cells of SMAs seen in wild-type embryos. CXCR4 is specifically expressed in arteries in the developing mesenteries and its expression is severely reduced in CXCL12-/- embryos. Mice in which CXCR4 is specifically deleted in the endothelium reveal vascular defects identical to those observed in the conventional CXCR4-/- embryos. Together, CXCL12 acts on arterial endothelial cells of SMA to up-regulate CXCR4 and mediate the connection between the larger artery and neighboring capillary plexus in an organ-specific manner.
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PMID:The role of CXCL12 in the organ-specific process of artery formation. 1562 44

Notch is an intercellular signaling pathway related mainly to sprouting neo-angiogenesis. The objective of our study was to evaluate the angiogenic mechanisms involved in the vascular augmentation (sprouting/intussusception) after Notch inhibition within perfused vascular beds using the chick area vasculosa and MxCreNotch1(lox/lox) mice. In vivo monitoring combined with morphological investigations demonstrated that inhibition of Notch signaling within perfused vascular beds remarkably induced intussusceptive angiogenesis (IA) with resultant dense immature capillary plexuses. The latter were characterized by 40 % increase in vascular density, pericyte detachment, enhanced vessel permeability, as well as recruitment and extravasation of mononuclear cells into the incipient transluminal pillars (quintessence of IA). Combination of Notch inhibition with injection of bone marrow-derived mononuclear cells dramatically enhanced IA with 80 % increase in vascular density and pillar number augmentation by 420 %. Additionally, there was down-regulation of ephrinB2 mRNA levels consequent to Notch inhibition. Inhibition of ephrinB2 or EphB4 signaling induced some pericyte detachment and resulted in up-regulation of VEGFRs but with neither an angiogenic response nor recruitment of mononuclear cells. Notably, Tie-2 receptor was down-regulated, and the chemotactic factors SDF-1/CXCR4 were up-regulated only due to the Notch inhibition. Disruption of Notch signaling at the fronts of developing vessels generally results in massive sprouting. On the contrary, in the already existing vascular beds, down-regulation of Notch signaling triggered rapid augmentation of the vasculature predominantly by IA. Notch inhibition disturbed vessel stability and led to pericyte detachment followed by extravasation of mononuclear cells. The mononuclear cells contributed to formation of transluminal pillars with sustained IA resulting in a dense vascular plexus without concomitant vascular remodeling and maturation.
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PMID:Inhibition of Notch signaling induces extensive intussusceptive neo-angiogenesis by recruitment of mononuclear cells. 2388 Nov 68

The precise mechanisms of SDF-1 (CXCL12) in angiogenesis are not fully elucidated. Recently, we showed that Notch inhibition induces extensive intussusceptive angiogenesis by recruitment of mononuclear cells and it was associated with increased levels of SDF-1 and CXCR4. In the current study, we demonstrated SDF-1 expression in liver sinusoidal vessels of Notch1 knockout mice with regenerative hyperplasia by means of intussusception, but we did not detect any SDF-1 expression in wild-type mice with normal liver vessel structure. In addition, pharmacological inhibition of SDF-1/CXCR4 signalling by AMD3100 perturbs intussusceptive vascular growth and abolishes mononuclear cell recruitment in the chicken area vasculosa. In contrast, treatment with recombinant SDF-1 protein increased microvascular density by 34% through augmentation of pillar number compared to controls. The number of extravasating mononuclear cells was four times higher after SDF-1 application and two times less after blocking this pathway. Bone marrow-derived mononuclear cells (BMDC) were recruited to vessels in response to elevated expression of SDF-1 in endothelial cells. They participated in formation and stabilization of pillars. The current study is the first report to implicate SDF-1/CXCR4 signalling in intussusceptive angiogenesis and further highlights the stabilizing role of BMDC in the formation of pillars during vascular remodelling.
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PMID:SDF-1/CXCR4 signalling is involved in blood vessel growth and remodelling by intussusception. 3095 Jan 88