Consensus guidelines for the use and interpretation of angiogenesis assays

Abstract

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference.

Deciphering the relative roles of matrix metalloproteinase‐ and plasmin‐mediated matrix degradation during capillary morphogenesis using engineered hydrogels

“…We chose umbilical vein‐derived ECs and supporting cells derived from bone marrow, lung, and dermis to explore in our model because our prior work has suggested differential utilization of MMP‐ and plasmin‐mediated proteolysis with these combinations . Furthermore, this EC source has been utilized widely for understanding mechanisms of capillary morphogenesis . Though we did not specifically test ECs from other origins, an essential role for MMPs in capillary morphogenesis has been described for microvascular, macrovascular, and stem cell‐derived ECs as has a role for plasmin with ECs derived from both macrovascular and microvascular sources .…”

Application of microscale culture technologies for studying lymphatic vessel biology

“…Systematic exploration of the mediators of lymphangiogenesis under controlled culture conditions may help improve our fundamental understanding of the etiology of lymphatic pathologies. To this end, a significant advance in 3‐D culture models of lymphangiogenesis was previously reported by Bruyere et al who developed an ex vivo lymphatic ring assay, which was an adaptation of the widely used aortic ring assay for angiogenesis . In addition, the rat mesentery has effectively been used as an ex vivo model for comparing the effects of VEGF‐C on lymphatic and blood vessel sprouting density, and understanding the role of VEGF‐A in increasing the frequency of blood‐lymphatic misconnections .…”

“…A better understanding of how lymphatic vessels develop, grow, and function may be accommodated through the use of controllable experimental systems that mimic living tissue. Along these lines, it is well‐appreciated by vascular biologists and physiologists that research in blood vessel angiogenesis and vascular function has benefitted immensely from the development of an impressive breadth of dedicated ex vivo, in vivo, and in vitro bioassays and techniques . However, one can argue that comparable advances have not yet been made for studying lymphatic vessel biology, physiology, and lymphangiogenesis.…”

Tanshinol borneol ester, a novel synthetic small molecule angiogenesis stimulator inspired by botanical formulations for angina pectoris

“…This widely used model is particularly useful for studying neovascularization as it provides a more natural environment for endothelial cell recruitment and capillary formation (Zudaire & Cuttitta, ) and provides the opportunity for quantifying the effect of angiogenic stimulators and inhibitors more easily than others (CAM and rabbit corneal assay; Jain, Schlenger, Hockel, & Yuan, ). The drug can either be placed in the plug together with the test factor by mixing with the Matrigel matrix or be given to the host animal (Nowak‐Sliwinska et al, ). To investigate whether systemic administration of DBZ exhibits pro‐angiogenic effect, 48 mice were randomly assigned into six groups (eight mice per group), and the group size was based on the consensus guidelines for the use and interpretation of angiogenesis assays (Nowak‐Sliwinska et al, ), our previous studies, and power calculations (The power analysis was performed using G*power software suggests at least n = 5 are needed [α = .05, power (1‐β) = 0.90, effect size = 0.892]).…”

“…The drug can either be placed in the plug together with the test factor by mixing with the Matrigel matrix or be given to the host animal (Nowak‐Sliwinska et al, ). To investigate whether systemic administration of DBZ exhibits pro‐angiogenic effect, 48 mice were randomly assigned into six groups (eight mice per group), and the group size was based on the consensus guidelines for the use and interpretation of angiogenesis assays (Nowak‐Sliwinska et al, ), our previous studies, and power calculations (The power analysis was performed using G*power software suggests at least n = 5 are needed [α = .05, power (1‐β) = 0.90, effect size = 0.892]). An aliquot (500 μl) of phenol red free GFR‐Matrigel (BD, Bedford, USA) was injected s.c. into both groin areas of mice after anaesthesia with 1.25% avertin (0.2 ml .…”