Protein kinase C-delta (PKC-delta) plays a pivotal role in mediating thrombin-induced NF-kappaB activation and ICAM-1 expression in endothelial cells. However, the downstream mechanisms mediating its function are unclear. In this study, we show that PKC-delta-mediated activation of protein-tyrosine kinase Syk plays an important role in thrombin signaling of NF-kappaB activation and intercellular adhesion molecule-1 (ICAM-1) expression in endothelial cells. Stimulation of human vascular endothelial cells with thrombin resulted in a time-dependent phosphorylation of Syk on tyrosine 525 and 526, an indication of Syk activation. Inhibition of PKC-delta by pharmacological and genetic approaches prevented Syk activation by thrombin. These results place Syk downstream of PKC-delta in transmitting thrombin-activated signaling in endothelial cells. Consistent with this, thrombin-induced NF-kappaB activity and ICAM-1 expression were prevented by the expression of a kinase-defective mutant or RNA interference knockdown of Syk. Similarly, inhibiting Syk also impaired NF-kappaB activity and ICAM-1 expression induced by a constitutively active mutant of PKC-delta. Analysis of the NF-kappaB pathway showed that Syk contributes to thrombin-induced NF-kappaB activation by controlling its transactivation potential and that this response is associated with tyrosine phosphorylation of RelA/p65. Thus, these data unveil a novel pathway in which Syk signals downstream of PKC-delta to mediate thrombin induced ICAM-1 expression in endothelial cells by increasing transcriptional capacity of NF-kappaB via a mechanism that relies on tyrosine phosphorylation of RelA/p65.
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http://dx.doi.org/10.1074/jbc.M802094200 | DOI Listing |
Biochem Biophys Res Commun
January 2025
Department of Ultrasonography, Fuwai Yunnan Hospital, Chinese Academy of Medical, Sciences/Affiliated Cardiovascular Hospital of Kunming Medical University, Kunming, 650102, China. Electronic address:
Pulmonary arterial hypertension (PAH) is a syndrome characterized by increased pulmonary vascular resistance and elevated pulmonary artery pressure, ultimately leading to right heart failure and even death. Increasing evidence implicates the fat mass and obesity-associated protein (FTO) in various metabolic and inflammatory pathways; however, its role in pulmonary endothelial function and PAH remains largely unexplored. In this study, we examined the effects of endothelial cell-specific FTO knockout on PAH development.
View Article and Find Full Text PDFPLoS One
January 2025
Pharmaceutical Medicinal Chemistry & Drug Design Department, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt.
This study presents T-1-NBAB, a new compound derived from the natural xanthine alkaloid theobromine, aimed at inhibiting VEGFR-2, a crucial protein in angiogenesis. T-1-NBAB's potential to interacts with and inhibit the VEGFR-2 was indicated using in silico techniques like molecular docking, MD simulations, MM-GBSA, PLIP, essential dynamics, and bi-dimensional projection experiments. DFT experiments was utilized also to study the structural and electrostatic properties of T-1-NBAB.
View Article and Find Full Text PDFPLoS One
January 2025
Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Muenster, Muenster, Germany.
Weibel-Palade bodies (WPB) are secretory organelles exclusively found in endothelial cells and among other cargo proteins, contain the hemostatic von-Willebrand factor (VWF). Stimulation of endothelial cells results in exocytosis of WPB and release of their cargo into the vascular lumen, where VWF unfurls into long strings of up to 1000 µm and recruits platelets to sites of vascular injury, thereby mediating a crucial step in the hemostatic response. The function of VWF is strongly correlated to its structure; in order to fulfill its task in the vascular lumen, VWF has to undergo a complex packing/processing after translation into the ER.
View Article and Find Full Text PDFInt J Surg
January 2025
Division of Cardiology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
Background: This study tested the hypothesis that extracorporeal shockwave therapy (ECSWT) effectively rescues critical limb ischemia (CLI) in mice through the upregulation of GPR120, which protects against inflammation and angiogenesis to restore blood flow in the ischemic area.
Methods And Results: Compared with the control, ECSWT-induced GPR120-mediated anti-inflammatory effects significantly suppressed the expression of inflammatory signaling biomarkers (TAK1/MAPK family/NF-κB/IL-1β/IL-6/TNF-α/MCP-1) in HUVECs, and these effects were abolished by silencing GPR120 or by the GPR120 antagonist AH7614 (all P < 0.001).
Biochem Genet
January 2025
Department of Pulmonary Disease, Shanghai Municipal Hospital of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200071, China.
Angiotensin-converting enzyme 2 (ACE2) has been reported to exert a protective effect in acute lung injury (ALI), though its underlying mechanism remains incompletely understood. In this study, ACE2 expression was found to be upregulated in a mouse model of ALI induced by lipopolysaccharide (LPS) injection. ACE2 knockdown modulated the severity of ALI, the extent of autophagy, and the mTOR pathway in this model.
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