RESUMO
BACKGROUND: The long isoform of the Wnk1 (with-no-lysine [K] kinase 1) is a ubiquitous serine/threonine kinase, but its role in vascular smooth muscle cells (VSMCs) pathophysiology remains unknown. METHODS: AngII (angiotensin II) was infused in Apoe-/- to induce experimental aortic aneurysm. Mice carrying an Sm22-Cre allele were cross-bred with mice carrying a floxed Wnk1 allele to specifically investigate the functional role of Wnk1 in VSMCs. RESULTS: Single-cell RNA-sequencing of the aneurysmal abdominal aorta from AngII-infused Apoe-/- mice revealed that VSMCs that did not express Wnk1 showed lower expression of contractile phenotype markers and increased inflammatory activity. Interestingly, WNK1 gene expression in VSMCs was decreased in human abdominal aortic aneurysm. Wnk1-deficient VSMCs lost their contractile function and exhibited a proinflammatory phenotype, characterized by the production of matrix metalloproteases, as well as cytokines and chemokines, which contributed to local accumulation of inflammatory macrophages, Ly6Chi monocytes, and γδ T cells. Sm22Cre+Wnk1lox/lox mice spontaneously developed aortitis in the infrarenal abdominal aorta, which extended to the thoracic area over time without any negative effect on long-term survival. AngII infusion in Sm22Cre+Wnk1lox/lox mice aggravated the aortic disease, with the formation of lethal abdominal aortic aneurysms. Pharmacological blockade of γδ T-cell recruitment using neutralizing anti-CXCL9 antibody treatment, or of monocyte/macrophage using Ki20227, a selective inhibitor of CSF1 receptor, attenuated aortitis. Wnk1 deletion in VSMCs led to aortic wall remodeling with destruction of elastin layers, increased collagen content, and enhanced local TGF-ß (transforming growth factor-beta) 1 expression. Finally, in vivo TGF-ß blockade using neutralizing anti-TGF-ß antibody promoted saccular aneurysm formation and aorta rupture in Sm22 Cre+ Wnk1lox/lox mice but not in control animals. CONCLUSION: Wnk1 is a key regulator of VSMC function. Wnk1 deletion promotes VSMC phenotype switch toward a pathogenic proinflammatory phenotype, orchestrating deleterious vascular remodeling and spontaneous severe aortitis in mice.
RESUMO
INTRODUCTION: Accumulating evidence demonstrates the importance of the galectin protein Placental Protein 13 (PP13) in predicting Preeclampsia (PE), a gestational disorder that has no cure and is associated with a compromised uterine vascular adaptation to pregnancy. Uterine vasculature undergoes significant remodeling (growth in length and in circumference) during normal pregnancy to accommodate the increased blood volume to the feto-placental unit. The aim of this study was to demonstrate the role of PP13 on the uterine veins (UVs). METHODS: PP13 was tested on UVs isolated from rat by using a pressurized myograph. The PP13 investigation was carried out in the presence of: a) nitric oxide synthases inhibitors (l-NAME + L-NNA, 2 x 10-4 M); b) small conductance Ca2+-activated K+ channels (SKca) inhibitor (Apamin, 10-7 M); c) intermediate conductance Ca2+-activated K+ channels (IKca) inhibitor (TRAM-34, 10-5 M); d) big conductance Ca2+-activated K+ channels (BKca) inhibitor (Paxilline, 10-5 M) and in the absence of endothelium. RESULTS: Our results showed that in late pregnancy, PP13 induced a significant dilation of UVs that is endothelium dependent. Further, PP13-dilation is mediated by the SKca - NO - BKca pathway. DISCUSSION: For the first time, this study provides evidence that in pregnancy, the UVs are dilated by PP13 and suggests SKCa as a potential target for treatments aimed at restoring pregnancy complication associated with deficiency in uterine adaptation.
