Mouse models of growth hormone insensitivity

Area of Science:

• Endocrinology
• Genetics
• Metabolic Research

Background:

• Growth hormone (GH) regulates growth and metabolism via the growth hormone receptor (GHR).
• Growth hormone insensitivity (GHI) is characterized by resistance to GH action, leading to insulin-like growth factor I (IGF-I) deficiency.
• GHI arises from genetic defects in GHR or downstream signaling pathways, exemplified by Laron Syndrome.

Purpose of the Study:

• To review the phenotypes of various genetically engineered mouse models of GHI.
• To elucidate the physiological impact of GHI on metabolism, growth, and overall health using these models.
• To highlight the utility of mouse models in understanding GH action in health, disease, and aging.

Main Methods:

• Review of existing literature on genetically altered mouse lines exhibiting GHI.
• Analysis of phenotypes in GHR knockout mice (GHR-/-), including the Laron mouse model.
• Examination of mice with temporal GHR loss (aGHRKO), GHR antagonist expression (GHA mice), and tissue-specific GHI (Cre-lox models).
• Inclusion of mouse models with defects in post-receptor signaling pathways.

Main Results:

• GHR-/- mice exhibit a complete lack of functional GHR, serving as a model for severe GHI.
• Temporal and tissue-specific GHR alterations in mouse models allow for nuanced investigation of GH action.
• Defects in post-receptor signaling pathways in mice further delineate the complex GHI landscape.
• These models collectively demonstrate the critical role of GH signaling in physiological processes.

Conclusions:

• Genetically engineered mouse models are essential tools for dissecting the complex mechanisms of GHI.
• These models provide valuable insights into the multifaceted roles of GH in growth, metabolism, health, and aging.
• Further research using these models will continue to advance our understanding of GH physiology and related disorders.