Publications by authors named "M Saifeddine"

Biocompatible polymeric nanoparticles (NPs) as carriers for therapeutic agents with multifunctional activities have received unprecedented attention for a variety of bio-pharmaceutical applications. We describe the synthesis, the fluorescence properties, the bio-compatible nature and the alpha-1 adrenergic receptor bio-activity of engineered quantum dot-like polynorepinephrine (PNE) NPs. The spherical PNE NPs, which are internalized in smooth muscle cells a receptor-selective mechanism, activate alpha-1-adrenoceptors in intact mouse aorta and aorta-derived cultured smooth muscle cells, leading to the activation of calcium signaling/contraction and stimulation of mitogen-activated protein kinase (MAPK), thereby displaying receptor-triggering biological activity, possibly acting both extracellularly and intracellularly.

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Background And Purpose: Chymotrypsin is a pancreatic protease secreted into the lumen of the small intestine to digest food proteins. We hypothesized that chymotrypsin activity may be found close to epithelial cells and that chymotrypsin signals to them via protease-activated receptors (PARs). We deciphered molecular pharmacological mechanisms and gene expression regulation for chymotrypsin signalling in intestinal epithelial cells.

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Article Synopsis
  • (+)-JQ1, a BET protein inhibitor, was found to reduce smooth muscle cell contraction and influence endothelial function by affecting calcium levels and myosin phosphorylation.
  • In experiments, (+)-JQ1 inhibited aortic contractile responses in both normal and endothelial-deficient mice, showing its effects were not reliant on BRD4.
  • The study revealed that the drug's action involved activating pathways related to nitric oxide production and was confirmed to have effects even without inhibiting BET proteins, suggesting a potential off-target action on vascular contractility.
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Variants in the RNA binding protein (RBP) U2AF2 are hypothesized to cause a novel neurodevelopmental disorder. Here, we report a patient with a de novo missense variant in U2AF2, the second case report of the same variant, and third case report overall. The patient in this report has a history of global developmental delay, dysmorphic features, and epilepsy.

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Giardia duodenalis cysteine proteases have been identified as key virulence factors and have been implicated in alterations to intestinal goblet cell activity and mucus production during Giardia infection. The present findings demonstrate a novel mechanism by which Giardia cysteine proteases modulate goblet cell activity via cleavage and activation of protease-activated receptor 2. Giardia duodenalis (assemblage A) increased MUC2 mucin gene expression in human colonic epithelial cells in a manner dependent upon both protease-activated receptor 2 activation and Giardia cysteine protease activity.

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