Aims: Sphingosine-1-phosphate (S1P) is a cellular signalling lipid generated by sphingosine kinase-1 (SPHK1). The aim of the study was to investigate whether the activated coagulation factor-X (FXa) regulates SPHK1 transcription and the formation of S1P and subsequent mitogenesis and migration of human vascular smooth muscle cells (SMC).
Methods And Results: FXa induced a time- (3-6 h) and concentration-dependent (3-30 nmol/L) increase of SPHK1 mRNA and protein expression in human aortic SMC, resulting in an increased synthesis of S1P. FXa-stimulated transcription of SPHK1 was mediated by the protease-activated receptor-1 (PAR-1) and PAR-2. In human carotid artery plaques, expression of SPHK1 was observed at SMC-rich sites and was co-localized with intraplaque FX/FXa content. FXa-induced SPHK1 transcription was attenuated by inhibitors of Rho kinase (Y27632) and by protein kinase C (PKC) isoforms (GF109203X). In addition, FXa rapidly induced the activation of the small GTPase Rho A. Inhibition of signalling pathways which regulate SPHK1 expression, inhibition of its activity or siRNA-mediated SPHK1 knockdown attenuated the mitogenic and chemotactic response of human SMC to FXa.
Conclusion: These data suggest that FXa induces SPHK1 expression and increases S1P formation independent of thrombin and that this involves the activation of Rho A and PKC signalling. In addition to its key function in coagulation, this direct effect of FXa on human SMC may increase cell proliferation and migration at sites of vessel injury and thereby contribute to the progression of vascular lesions.
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http://dx.doi.org/10.1093/cvr/cvt112 | DOI Listing |
Se Pu
January 2025
School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, China.
Cell Death Dis
December 2024
Department of Neurosurgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, 450000, China.
Intracerebral hemorrhage (ICH) is a severe stroke subtype with high mortality and limited therapeutic options. The blood-brain barrier (BBB) breakdown post-ICH exacerbates secondary brain injury, highlighting the need for targeted therapies to preserve the BBB integrity. We aim to investigate the role of the Sphk1/S1P pathway in BBB breakdown following ICH and to evaluate the therapeutic potential of Sphk1 inhibition in mitigating this breakdown.
View Article and Find Full Text PDFCancers (Basel)
November 2024
Department of Pharmacology, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA.
Our recent studies have identified a link between sphingolipid metabolites and the induction of a specialized form of regulated cell death termed immunogenic cell death (ICD). We have recently demonstrated that the synthetic cannabinoid (±) 5-epi CP 55,940 (5-epi) stimulates the accumulation of ceramide (Cer), and that inhibition of sphingosine kinase 1 (SphK1) enhances Cer accumulation and ICD-induction in human colorectal cancer (CRC) cell lines. We employed flow-cytometric, western blot analyses, pharmacological inhibitors of the sphingolipid metabolic pathway and small molecule agonists and antagonists of the CB receptors to further analyze the mechanism by which 5-epi induces Cer accumulation.
View Article and Find Full Text PDFComput Methods Biomech Biomed Engin
December 2024
Department of Hepatobiliary Surgery, Quzhou Hospital Affiliated of Wenzhou Medical University (Quzhou People's Hospital), Quzhou, Zhejiang, China.
Background: The prognosis of cancers is strongly connected with nitrogen metabolism (NM), which plays a critical role in the microenvironment and growth of tumors. It is unsubstantiated, however, how important NM-related genes are for the prognosis of hepatocellular carcinoma (HCC).
Methods: Using publicly available data, we examined potential mechanisms of NM-related genes in HCC, created a predictive model, and assessed immune infiltration and medication sensitivity.
Naunyn Schmiedebergs Arch Pharmacol
December 2024
Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
Diabetic testicular dysfunction (DTD) poses a significant threat to male reproductive health. This study delves into the potential of piperazine ferulate (PF), a natural phenolic compound, in alleviating DTD and sheds light on its underlying mechanisms in rats. Animals were divided into the control, PF, diabetic, and diabetic plus PF groups.
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