Nakakura T, Horiguchi K, Suzuki T. Collagen XIII Is the Key Molecule of Neurovascular Junctions in the Neuroendocrine System.
Neuroendocrinology 2024;
114:658-669. [PMID:
38643753 DOI:
10.1159/000538976]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 04/16/2024] [Indexed: 04/23/2024]
Abstract
INTRODUCTION
Axons of magnocellular neurosecretory cells project from the hypothalamus to the posterior lobe (PL) of the pituitary. In the PL, a wide perivascular space exists between the outer basement membrane (BM), where nerve axons terminate, and the inner BM lining the fenestrated capillaries. Hypothalamic axon terminals and outer BMs in the PL form neurovascular junctions. We previously had found that collagen XIII is strongly localized in the outer BMs. In this study, we investigated the role of collagen XIII in the PL of rat pituitaries.
METHODS
We first studied the expression of Col13a1, the gene encoding the α1 chains of collagen XIII, in rat pituitaries via quantitative real-time polymerase chain reaction and in situ hybridization. We observed the distribution of COL13A1 in the rat pituitary using immunohistochemistry and immunoelectron microscopy. We examined the expression of Col13a1 and the distribution of COL13A1 during the development of the pituitary. In addition, we examined the effects of water deprivation and arginine vasopressin (AVP) signaling on the expression of Col13a1 in the PL.
RESULTS
Col13a1 was expressed in NG2-positive pericytes, and COL13A1 signals were localized in the outer BM of the PL. The expression of Col13a1 was increased by water deprivation and was regulated via the AVP/AVPR1A/Gαq/11 cascade in pericytes of the PL.
CONCLUSION
These results suggest that pericytes surrounding fenestrated capillaries in the PL secrete COL13A1 and are involved in the construction of neurovascular junctions. COL13A1 is localized in the outer BM surrounding capillaries in the PL and may be involved in the connection between capillaries and axon terminals.
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