Bioengineering an improved three-dimensional vascularized co-culture model for studying Neuron-Microglia...

Area of Science:

• Neuroscience
• Regenerative Medicine
• Biomaterials Engineering

Background:

• The neurovascular unit (NVU), comprising neurons, microglia, and endothelial cells (ECs), is crucial for central nervous system (CNS) homeostasis and neurological disorders.
• Limited understanding of NVU crosstalk stems from a lack of physiologically relevant in vitro models.

Purpose of the Study:

• To develop an improved 3D vascularized tri-culture model integrating human-induced neural stem cells (hiNSCs), human vascular organoids (hVOs), and microglia.
• To investigate cell-type-specific interactions within the CNS microenvironment and their impact on neurovascular development.

Main Methods:

• A geometrically engineered silk fibroin scaffold was used to create a 3D tri-culture system with hiNSCs, hVOs, and microglia.
• The model recapitulated spatial neurovascular patterning and allowed for the study of cell interactions.

Main Results:

• hVOs promoted hiNSC neuronal differentiation, axonal growth, and neurovascular alignment.
• Microglial phenotype influenced outcomes: M0 and M1 microglia inhibited differentiation, with M1 showing the strongest effect.
• M2 microglia exhibited minimal inhibition and supported neurovascular maturation, cooperating with hVOs via SDF-1/CXCR4 signaling to enhance neuronal differentiation.

Conclusions:

• This 3D co-culture model provides a physiologically relevant platform for studying neuroimmune and neurovascular interactions.
• The findings highlight the crucial role of M2 microglia and the SDF-1/CXCR4 axis in promoting neurovascular development.
• The model has potential for research in neurodevelopment, neurodegeneration, drug screening, and regenerative therapies.