Multiple endocrine defects in adult-onset Sprouty1/2/4 triple knockout mice

Area of Science:

• Molecular Biology
• Endocrinology
• Developmental Biology

Background:

• Sprouty genes (Spry1-4) are key feedback inhibitors of receptor tyrosine kinases, crucial for embryonic development.
• Their roles in adult physiology and tumor suppression are less understood compared to their embryonic functions.

Purpose of the Study:

• To investigate the physiological and tumor-related consequences of adult-onset, whole-body Sprouty gene deficiency.
• To determine if Sprouty loss is sufficient for tumorigenesis in adult mice.

Main Methods:

• Generation of adult-onset, whole-body Spry1/2/4 triple knockout mice.
• Comparative analysis of tumor incidence, body weight, metabolism, and endocrine function between knockout and wild-type mice.

Main Results:

• Triple knockout mice showed no increased tumor incidence up to one year of age.
• Significant metabolic changes observed: reduced weight gain, less visceral fat, lower plasma glucose, and phosphaturia with hypophosphatemia.
• Endocrine abnormalities included alopecia, eyelid inflammation, and mild hyperthyroidism, suggesting dysregulated FGF23 signaling.

Conclusions:

• Sprouty gene loss alone is insufficient to initiate tumorigenesis in adult mice.
• Complete loss of Sprouty function leads to a spectrum of endocrine and metabolic dysregulations in adult mice.
• These findings reveal critical roles for Sprouty genes in maintaining adult physiological homeostasis.