Semaphorin3a regulates endothelial cell number and podocyte differentiation during glomerular development

Area of Science:

• Nephrology
• Developmental Biology
• Molecular Biology

Background:

• Semaphorin3a (Sema3a) is a guidance protein involved in vascular patterning.
• Sema3a is expressed in the developing and mature kidney.
• Its role in glomerular development was previously unexamined.

Purpose of the Study:

• To investigate the role of Sema3a in glomerular vascular development.
• To test the hypothesis that Sema3a regulates glomerular vascular development.

Main Methods:

• Utilized loss- and gain-of-function mouse models.
• Analyzed renal vascular patterning, glomerular structure, and podocyte morphology.
• Assessed markers of kidney function like albuminuria and proteinuria.

Main Results:

• Sema3a deletion caused renal vascular defects, increased glomerular endothelial cells, podocyte effacement, and albuminuria.
• Sema3a overexpression led to glomerular hypoplasia, endothelial cell apoptosis, abnormal podocyte development, and proteinuria.
• Downregulation of Nephrin, WT1, and VEGFR2 was observed in Sema3a-overexpressing kidneys.

Conclusions:

• Sema3a is a critical negative regulator of endothelial cell survival in developing glomeruli.
• Sema3a is essential for proper podocyte differentiation and glomerular filtration barrier formation.
• Appropriate Semaphorin3a levels are necessary for normal kidney development.