The Multifaceted Roles of Pituitary Pericytes in Health and Disease.

Pericytes are mural cells distributed in the basement membrane of precapillary arterioles, capillaries, and postcapillary venules and are indispensable parts of the vascular microenvironment. To date, pericytes have been found to play a crucial role in vascular homeostasis in several organs. The pituitary gland has a complex network of blood vessels that support endocrine function; thus, pericytes also have irreplaceable functions in the pituitary vascular microenvironment, including angiogenesis, vascular regulation, neuroendocrine, extracellular matrix regulation, and mesenchymal-like differentiation potential. Notably, emerging evidence suggests potential functional heterogeneity between anterior and posterior pituitary pericytes, which may underlie their specialized roles in regulating lobe-specific vascular and neuroendocrine activities. Additionally, the underlying impact of pericytes on pituitary lesions, such as tumors, apoplexy, and fibrosis, has been revealed in the past decade. In this review, we introduce the fundamental characteristics of pituitary pericytes on the basis of their morphological characteristics, molecular markers, and origin; emphasize their multiple functions under physiological conditions; and explore their latent role in pituitary diseases. This review is the first to provide a comprehensive overview of the physiological functions and pathological mechanisms of pituitary pericytes, in an attempt to develop new ideas for future research.