Icariside Ⅱ Attenuates Palmitic Acid-Induced Endothelial Dysfunction Through SRPK1-Akt-eNOS Signaling Pathway

Abstract

Background: Endothelial dysfunction is commonly accompanied by a reduced capacity for nitric oxide (NO) production and decreased NO sensitivity, playing a central role in numerous vascular diseases. Saturated free fatty acids are known to reduce NO production and then induce endothelial dysfunction. Alternative splicing participates in the regulation of cellular and tissular homeostasis and is highly regulated by serine-arginine protein kinase (SRPK1). The role of SRPK1 in the biology of endothelial cells remains elusive. Icariside Ⅱ (ICA Ⅱ) has been reported to have protective effects on endothelial function. However, the specific molecular mechanisms are still unknown. The purpose of this study is to explore the role of SRPK1 in the biology of endothelial cells and the underlying mechanism of ICA Ⅱ on palmitic acid (PA) induced endothelial dysfunction.Methods: Endothelial dysfunction was induced using PA in human umbilical vein endothelial cells (HUVECs). The expression and phosphorylation of related proteins in the SRPK1-Akt-eNOS signaling pathway were detected by Western Blot. Cell Counting Kit-8 assay and Ki-67 immunofluorescence were used to estimate cell viability. Endothelial cell function was assessed by detecting NO production using DAF-FM DA. Interaction between ICA Ⅱ and SRPK1 was demonstrated by a biotinylated protein interaction pull-down assay.Results: The expressions of eNOS, Akt, and SRPK1 were down-regulated in the endothelial dysfunction stimulated by PA. SRPK1 inhibitor SPHINX31 restrained endothelial cell viability in a dose-dependent manner. Moreover, inhibition of SRPK1 using SPHINX31 and knockdown of SRPK1 by shRNA also showed a down-regulation of the proteins associated with the SRPK1-Akt-eNOS signaling pathway. Biotinylated protein interaction pull-down assay revealed that ICA Ⅱ could be directly bound with SRPK1. On the other hand, ICA Ⅱ could attenuate the PA-induced endothelial dysfunction and restore cell viability through the SRPK1-Akt-eNOS pathway.Conclusions: ICA Ⅱ, bound with SRPK1, could attenuate the endothelial dysfunction induced by the PA in HUVECs via the SRPK1-Akt-eNOS signaling pathway.

SUMOylation and coupling of eNOS mediated by PIAS1 contribute to maintenance of vascular homeostasis

“…12 Furthermore, research has demonstrated that icariside II has the ability to mitigate endothelial dysfunction induced by PA and to restore cell viability through the SRPK1-Akt-eNOS pathway. 14 In the study, we found that PIAS1 alleviates the ED induced by PA in vitro or by HFD in vivo by activating the PI3K-AKT-eNOS pathway, increasing NO levels, and reducing MDA levels. Studies have shown that the proliferation and migration of endothelial cells play an important role in angiogenesis.…”

“…It has been shown that PIAS1 deficiency impairs yolk sac erythropoiesis and vasculogenesis, leading to defective capillary plexus formation and blood vessel occlusions in vivo 12 . Furthermore, research has demonstrated that icariside II has the ability to mitigate endothelial dysfunction induced by PA and to restore cell viability through the SRPK1‐Akt‐eNOS pathway 14 . In the study, we found that PIAS1 alleviates the ED induced by PA in vitro or by HFD in vivo by activating the PI3K‐AKT‐eNOS pathway, increasing NO levels, and reducing MDA levels.…”

“…The cells were evenly seeded into six culture dishes and randomly divided into six groups including control (Ctrl), Ctrl+Vehicle, Ctrl+PIAS1, PA, PA + Vehicle and PA + PIAS1. First, PA stock solution was prepared following the previous reports 14,15 . Next, the ED model in vitro was established with 0.3 mM PA treatment for 24 h. After modeling, HUVECs were infected with the adenoviruses carrying either PIAS1 or Vehicle with an optimal titer (MOI = 100).…”

“…First, PA stock solution was prepared following the previous reports. 14,15 Next, the ED model in vitro was established with 0.3 mM PA treatment for 24 h. After modeling, HUVECs were infected with the adenoviruses carrying either PIAS1 or Vehicle with an optimal titer (MOI = 100).…”

Transcriptome analysis highlights the role of ferroptosis in palmitic acid–induced endothelial dysfunction

“…PA working solution (10 mM) was prepared as described previously. 10 , 11 Briefly, fine-powdered PA (Cat# HY-N0830, MCE, Shanghai, China) was fully dissolved in ethanol, mixed with 10% fatty acid-free bovine serum albumin (Cat# A8850, Solarbio, Beijing, China), co-incubated at 55°C in a water bath, filtered with 0.45-μm membranes, aliquoted into fractions, and stored at −80°C for up to 6 months.…”