Characterization of FGF21 Sites of Production and Signaling in Mice

Area of Science:

• Endocrinology
• Metabolic Regulation
• Molecular Biology

Background:

• Fibroblast growth factor (FGF) 21 is an endocrine hormone crucial for metabolic regulation.
• FGF21 and FGF15/19 signal through the co-receptor β-klotho (KLB), which is expressed in various metabolic tissues.
• While the liver is the primary source of circulating FGF21, brain-derived FGF21 influences cognitive functions.

Purpose of the Study:

• To comprehensively map the expression patterns of KLB and FGF21 throughout the body using reporter mice.
• To identify specific cell types and spatial distributions of KLB expression in metabolic tissues.
• To provide a foundational resource for understanding FGF signaling pathways and non-hepatic FGF21 roles.

Main Methods:

• Generation and utilization of reporter mouse models to visualize KLB and FGF21 expression.
• Comprehensive tissue analysis to determine the localization and cell-type specificity of KLB and FGF21.
• Integration of expression data to map FGF signaling networks.

Main Results:

• Detailed expression profiles of KLB and FGF21 across multiple peripheral and central tissues were established.
• Specific cellular and anatomical locations of KLB expression were identified in key metabolic organs.
• Evidence for FGF21 expression in non-hepatic tissues, including the brain, was confirmed.

Conclusions:

• The study provides a critical resource for identifying novel peripheral and central targets of FGF signaling.
• Understanding KLB and FGF21 distribution is essential for elucidating their roles in metabolic homeostasis and brain function.
• These findings pave the way for future research into the therapeutic potential of FGF21-targeting strategies.