Phoenixin‐14 maintains the contractile type of vascular smooth muscle cells in cerebral aneurysms rats

Abstract The rupture of intracranial aneurysm (IA) is the primary reason contributing to the occurrence of life‐threatening subarachnoid hemorrhages. The oxidative stress‐induced phenotypic transformation from the contractile phenotype to the synthetic phenotype of vascular smooth muscle cells (VSMCs) plays a pivotal role in IA formation and rupture. Our study aimed to figure out the role of phoenixin‐14 in VSMC phenotypic switching during the pathogenesis of IA by using both cellular and animal models. Primary rat VSMCs were isolated from the Willis circle of male Sprague‐Dawley rats. VSMCs were stimulated by hydrogen peroxide (H 2 O 2 ) to establish a cell oxidative damage model. After pretreatment with phoenixin‐14 and exposure to H 2 O 2 , VSMC viability, migration, and invasion were examined through cell counting kit‐8 (CCK‐8), wound healing, and Transwell assays. Intracellular reactive oxygen species (ROS) production in VSMCs was evaluated by using 2′,7′‐Dichlorofluorescin diacetate (DCFH‐DA) fluorescence probes and flow cytometry. Rat IA models were established by ligation of the left common carotid arteries and posterior branches of both renal arteries. The histopathological changes of rat intracranial blood vessels were observed through hematoxylin and eosin staining. The levels of contractile phenotype markers (alpha‐smooth muscle actin [α‐SMA] and smooth muscle 22 alpha [SM22α]) in VSMCs and rat arterial rings were determined through real‐time quantitative polymerase chain reaction (RT‐qPCR) and western blot analysis. Our results showed that H 2 O 2 stimulated the production of intracellular ROS and induced oxidative stress in VSMCs, while phoenixin‐14 pretreatment attenuated intracellular ROS levels in H 2 O 2 ‐exposed VSMCs. H 2 O 2 exposure promoted VSMC migration and invasion, which, however, was reversed by phoenixin‐14 pretreatment. Besides, phoenixin‐14 administration inhibited IA formation and rupture in rat models. The decrease in α‐SMA and SM22α levels in H 2 O 2 ‐exposed VSMCs and IA rat models was antagonized by phoenixin‐14. Collectively, phoenixin‐14 ameliorates the progression of IA through preventing the loss of the contractile phenotype of VSMCs.