Leukemia inhibitory factor regulates microvessel density by modulating oxygen-dependent VEGF expression in mice

Area of Science:

• Vascular biology
• Angiogenesis
• Cell signaling

Background:

• Capillary density is crucial for tissue oxygenation.
• Hypoxia-induced factors like HIFs and VEGF are key regulators of capillary formation.
• Additional mechanisms may fine-tune capillary network development.

Purpose of the Study:

• To investigate the role of leukemia inhibitory factor (LIF) in regulating capillary network formation.
• To explore the communication between tissues and vasculature in vascularization.
• To identify potential new strategies for anti-angiogenic therapies.

Main Methods:

• Studied Lif(-/-) mice to assess microvessel density and tip cell activity.
• Utilized an oxygen-induced retinopathy model to evaluate response to hyperoxia.
• Performed in vitro studies on cultured astrocytes to examine LIF's effect on VEGF expression and proliferation.

Main Results:

• Lif(-/-) mice exhibited increased retinal microvessel density and sustained tip cell activity, linked to elevated astrocyte VEGF expression.
• Lif(-/-) mice showed resistance to hyperoxia in retinopathy models but paradoxically increased neovascular tufts.
• In vitro, LIF inhibited hypoxia-induced VEGF expression and astrocyte proliferation.
• Increased microvessel density and VEGF upregulation were observed in various non-retinal tissues of Lif(-/-) mice.

Conclusions:

• LIF plays a significant role in regulating vascularization, acting in concert with oxygen levels.
• Tissues and advancing vasculature communicate via LIF to ensure adequate vascularization.
• Findings suggest LIF modulation as a novel strategy for anti-angiogenic therapies in diseases like diabetic retinopathy and cancer.