Bone circuitry and interorgan skeletal crosstalk

Area of Science:

• Skeletal Biology and Physiology
• Endocrinology
• Cellular Communication

Background:

• Significant advances in understanding skeletal homeostasis and disease mechanisms over the past decade.
• Breakthroughs stem from identifying disease mutations and modeling bone disease in rodents.
• Skeletal physiology is highly integrative, involving complex cellular and systemic interactions.

Purpose of the Study:

• To review recently elucidated mechanisms controlling bone remodeling.
• To discuss intercellular communication within the skeleton and with other organs.
• To explore therapeutic opportunities for skeletal diseases.

Main Methods:

• Review of recent scientific literature and breakthroughs.
• Analysis of studies involving genetic mutations and rodent models of bone disease.
• Examination of signaling pathways (e.g., RANK/RANKL/OPG, BMP, WNT) and molecular mediators.

Main Results:

• Bone cells (osteoblasts, osteoclasts, osteocytes) communicate via multiple pathways (e.g., RANK/RANKL/OPG, LXRs, WNT).
• The skeleton interacts with adjacent (bone marrow, muscle, fat) and remote organs (kidney, liver, brain).
• Bone-derived osteocalcin influences energy homeostasis; pituitary hormones play independent roles in skeletal remodeling.

Conclusions:

• Complex communication networks govern skeletal homeostasis and remodeling.
• Understanding these intricate connections offers new avenues for treating skeletal diseases.
• The endocrine-immune-skeletal connection is a critical area for future research.