The osteocyte is a critical cell in bone biology, functioning as an endocrine cell that regulates bone remodeling, mineral metabolism, and communication with distant organs. Unlike previously thought, osteocytes are not passive cells but actively involved in bone homeostasis. They regulate osteoclast and osteoblast activity, produce soluble factors that influence bone and other tissues, and play a role in phosphate and calcium metabolism. Osteocytes make up 90-95% of all bone cells and are the longest-living bone cells, surviving for decades. However, as individuals age, osteocytes die, leading to the formation of empty lacunae, which are associated with reduced bone remodeling. Inflammatory factors such as tumor necrosis factor and glucocorticoids can induce osteocyte death through different mechanisms, affecting bone health. Osteocytes originate from mesenchymal stem cells and undergo differentiation into osteoblasts, which then become osteocytes. This process is not passive but involves complex cellular changes, including the formation of dendritic processes and the regulation of mineralization. Osteocytes can also express markers typically associated with osteoclasts, indicating their multifunctional nature. They play a key role in bone remodeling by recruiting osteoclasts to sites of microdamage, and their death can lead to increased bone fragility. The Wnt/β-catenin signaling pathway is crucial for osteocyte function and viability. Negative regulators such as Dkk1 and sclerostin are highly expressed in osteocytes and influence bone formation. Sclerostin, in particular, inhibits osteoblast activity and is involved in the regulation of bone mass. Mechanical loading, such as fluid-flow shear stress, can protect osteocytes from apoptosis by activating the Wnt/β-catenin pathway and releasing prostaglandins. Osteocytes also play a role in mineral metabolism by regulating factors such as PHEX, DMP-1, MEPE, and FGF-23, which influence phosphate excretion and bone mineralization. Osteocytes are also mechanosensory cells, capable of sensing mechanical forces and transmitting signals to regulate bone formation and remodeling. They can respond to mechanical strain by releasing signaling molecules such as nitric oxide, ATP, and prostaglandins. Osteocytes can also undergo autophagy, a process that helps maintain cellular viability under stress conditions. The osteocyte lacunocanalicular network functions as an endocrine system, influencing distant organs such as the kidney. Understanding osteocyte biology is essential for developing therapies for bone diseases and metabolic disorders. Future research will focus on uncovering additional osteocyte functions and their potential therapeutic applications.The osteocyte is a critical cell in bone biology, functioning as an endocrine cell that regulates bone remodeling, mineral metabolism, and communication with distant organs. Unlike previously thought, osteocytes are not passive cells but actively involved in bone homeostasis. They regulate osteoclast and osteoblast activity, produce soluble factors that influence bone and other tissues, and play a role in phosphate and calcium metabolism. Osteocytes make up 90-95% of all bone cells and are the longest-living bone cells, surviving for decades. However, as individuals age, osteocytes die, leading to the formation of empty lacunae, which are associated with reduced bone remodeling. Inflammatory factors such as tumor necrosis factor and glucocorticoids can induce osteocyte death through different mechanisms, affecting bone health. Osteocytes originate from mesenchymal stem cells and undergo differentiation into osteoblasts, which then become osteocytes. This process is not passive but involves complex cellular changes, including the formation of dendritic processes and the regulation of mineralization. Osteocytes can also express markers typically associated with osteoclasts, indicating their multifunctional nature. They play a key role in bone remodeling by recruiting osteoclasts to sites of microdamage, and their death can lead to increased bone fragility. The Wnt/β-catenin signaling pathway is crucial for osteocyte function and viability. Negative regulators such as Dkk1 and sclerostin are highly expressed in osteocytes and influence bone formation. Sclerostin, in particular, inhibits osteoblast activity and is involved in the regulation of bone mass. Mechanical loading, such as fluid-flow shear stress, can protect osteocytes from apoptosis by activating the Wnt/β-catenin pathway and releasing prostaglandins. Osteocytes also play a role in mineral metabolism by regulating factors such as PHEX, DMP-1, MEPE, and FGF-23, which influence phosphate excretion and bone mineralization. Osteocytes are also mechanosensory cells, capable of sensing mechanical forces and transmitting signals to regulate bone formation and remodeling. They can respond to mechanical strain by releasing signaling molecules such as nitric oxide, ATP, and prostaglandins. Osteocytes can also undergo autophagy, a process that helps maintain cellular viability under stress conditions. The osteocyte lacunocanalicular network functions as an endocrine system, influencing distant organs such as the kidney. Understanding osteocyte biology is essential for developing therapies for bone diseases and metabolic disorders. Future research will focus on uncovering additional osteocyte functions and their potential therapeutic applications.