Žaloudíková M, Eckhardt A, Vytášek R, Uhlík J, Novotný T, Bačáková L, Musílková J, Hampl V. Decreased collagen VI in the tunica media of pulmonary vessels during exposure to hypoxia: a novel step in pulmonary arterial remodeling.
Pulm Circ 2019;
9:2045894019860747. [PMID:
31187694 PMCID:
PMC6625215 DOI:
10.1177/2045894019860747]
[Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The development of hypoxic pulmonary hypertension is characterized by the
structural remodeling of pulmonary arteries. However, the relationship between
changes of arterial cells and the extracellular matrix remains unclear. We
focused on the evaluation of the non-fibrillar collagen changes in tunica media
induced by a four-day exposure to hypoxia and the correlation of these changes
with the pulmonary arterial wall structure modifications. We used 20 adult male
Wistar rats. The amount and localization of collagen VI, collagen IV, matrix
metalloproteinase (MMP) 2, and MMP9 were tested in pulmonary arteries
immunohistochemically. Two-dimensional electrophoresis and messenger RNA (mRNA)
expression were used for the subsequent comparison of protein changes in
arterial tunica media cells (normoxia/hypoxia). Collagen VI was significantly
reduced strictly in the tunica media of conduit arteries of hypoxia-exposed
rats; however, its mRNA increased. The amount of collagen IV and its mRNA were
not altered. We detected a significant increase of MMP9 strictly in the tunica
media. In addition, a significantly increased number of MMP9-positive cells
surrounded the arteries. MMP2 and the expression of its mRNA were decreased in
tunica media. We conclude that the loss of collagen VI is an important step
characterizing the remodeling of pulmonary arteries. It could influence the
phenotypic status and behavior of smooth muscle cells and modify their
proliferation and migration.
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