Introduction: The endotoxin lipopolysaccharide (LPS)-induced pulmonary endothelial barrier disruption is a key pathogenesis of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). However, the molecular mechanisms underlying LPS-impaired permeability of pulmonary microvascular endothelial cells (PMVECs) are not fully understood.
Methods: Rat PMVECs were isolated and monolayered cultured, then challenged with different doses of LPS (0.1mg/L, 1mg/L, and 10mg/L). Trans-endothelial electrical resistance (TER) was utilized to measure the integrity of the endothelial barrier. Ras-related C3 botulinum toxin substrate 1 (Rac1) activity and the phosphorylation of Ezrin/Radixin/Moesin proteins (ERM) were assessed by pulldown assay and Western Blotting. Small interfering RNA (siRNA) inhibition of Rac1 and Moesin were applied to evaluate the effect of PMVEs permeability and related pathway.
Results: LPS induced dose and time-dependent decreases in TER and increase in ERM threonine phosphorylation, while inactivated Rac1 activity in PMVEC. siRNA study demonstrated that both Rac1 and Moesin were involved in the mediation of the LPS-induced hyperpermeability in PMVECs monolayers, and Rac1 and Moesin could regulate each other.
Conclusion: Phosphorylated ERM mediates LPS induced PMVECs permeability through negatively regulating Rac1 activity.
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http://dx.doi.org/10.1016/j.arbres.2018.09.014 | DOI Listing |
Cardiovasc Res
January 2025
Department of Pharmacology, School of Basic Medicine, Tongji Medical College and State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
Aims: Dedicator of Cytokinesis 2 (DOCK2), a member of the DOCK family of Guanine nucleotide exchange factors that specifically act on the Rho GTPases including Rac and Cdc42, plays pivotal roles in the regulation of leukocyte homeostasis. However, its functions in platelets remain unknown.
Methods And Results: Using mice with genetic deficiency of DOCK2 (Dock2-/-), we showed that Dock2-/-mice exhibited a macrothrombocytopenic phenotype characterized as decreased platelet count and enlarged platelet size by transmission electron microscopy.
Food Funct
January 2025
State Key Laboratory for Diagnosis and Treatment of Severe Zoonotic Infectious Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine Jilin University, Center of Infectious Diseases and Pathogen Biology, Department of Infectious Diseases, First Hospital of Jilin University, Changchun, China.
serovar Typhimurium (STM) causes severe colitis, necessitating the development of effective drugs. Here, the dockings of limonin with the STM T3SS-1 virulence factor SopB or SopE2 showed strong binding activity and was verified by CETSA and DARTS assays . Limonin inhibited the enzyme activities and expression of SopB and SopE2 .
View Article and Find Full Text PDFCell Mol Biol Lett
January 2025
PhD Program in Medical Neuroscience, Taipei Medical University, Taipei, Taiwan (R.O.C.).
Background: Regulation of messenger RNA (mRNA) transport and translation in neurons is essential for dendritic plasticity and learning/memory development. The trafficking of mRNAs along the hippocampal neuron dendrites remains translationally silent until they are selectively transported into the spines upon glutamate-induced receptor activation. However, the molecular mechanism(s) behind the spine entry of dendritic mRNAs under metabotropic glutamate receptor (mGluR)-mediated neuroactivation and long-term depression (LTD) as well as the fate of these mRNAs inside the spines are still elusive.
View Article and Find Full Text PDFCells under high confinement form highly polarized hydrostatic pressure-driven, stable leader blebs that enable efficient migration in low adhesion, environments. Here we investigated the basis of the polarized bleb morphology of metastatic melanoma cells migrating in non-adhesive confinement. Using high-resolution time-lapse imaging and specific molecular perturbations, we found that EGF signaling via PI3K stabilizes and maintains a polarized leader bleb.
View Article and Find Full Text PDFAnim Cells Syst (Seoul)
January 2025
School of Biological Sciences, Seoul National University, Seoul, Republic of Korea.
βPix is a guanine nucleotide exchange factor for the Rac1 and Cdc42 small GTPases, which play important roles in dendritic spine morphogenesis by modulating actin cytoskeleton organization. The formation and plasticity of the dendritic spines are essential for normal brain function. Among the alternatively spliced βPix isoforms, βPix-b and βPix-d are expressed specifically in neurons.
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