Chrebp Deletion and Mild Protein Restriction Additively Decrease Muscle and Bone Mass and Function.

Area of Science:

• Metabolic regulation
• Nutritional science
• Musculoskeletal health

Background:

• Carbohydrate and protein restriction are linked to sarcopenia and osteopenia, but mechanisms are unclear.
• Investigating the impact of mild protein restriction on muscle and bone in wild-type (WT) and ChREBP knockout (KO) mice.

Purpose of the Study:

• To determine the effects of mild protein restriction on muscle and bone function in WT and ChREBP KO mice.
• To elucidate the underlying mechanisms contributing to potential muscle and bone deficits.

Main Methods:

• Eighteen-week-old male WT and ChREBP KO mice were fed control (20% protein) or low-protein (15% protein) diets for 12 weeks.
• Assessed muscle weight, limb grip strength, bone mineral density (BMD), bone structure, and bone morphometry.

Main Results:

• ChREBP deletion and low-protein diet additively decreased body weight, fat weight, muscle weight, and limb grip strength.
• These muscle deficits were associated with decreased insulin/IGF-1 mRNA and increased myostatin mRNA.
• ChREBP deletion increased BMD and bone structural integrity, but protein restriction in KO mice reversed these benefits, decreasing BMD and stiffness. Mild protein restriction reduced bone formation markers only in WT mice.

Conclusions:

• Both ChREBP deletion and protein restriction impair muscle and bone function, suggesting a role for ChREBP in musculoskeletal health.
• Adequate carbohydrate and protein intake is essential for maintaining muscle and bone mass and function.
• Further research is needed to fully understand the mechanisms behind ChREBP deletion and low-protein diet-induced osteosarcopenia.