title: β2-Glycoprotein-I based peptide regulate endothelial-cells tissue-factor expression via negative regulation of pGSK3β expression and reduces experimental-antiphospholipid-syndrome.
abstract: Antiphospholipid syndrome (APS) is characterized by thromboembolic phenomena and recurrent fetal loss associated with elevated circulating anti-phospholipid/beta2glycoprotein-I(β2GPI)-binding-antibodies(Abs). Individual APS patients harbor diverse clusters of circulating anti-β2GPI Abs, targeting different epitopes on the β2GPI molecule. Our novel approach was to construct a peptide composed of β2GPI-ECs-binding-site (phospholipids-membrane), named "EMBI". EMBI exert dual activities: a) At first EMBI prevented β2GPI ECs binding, thus reduced by 89% the binding of β2GPI/anti-β2GPI to the cells in comparison with 9.3% inhibition by EMBI scrambled form (scEMBI). b) Longer exposure of ECs to EMBI resulted in intracellular EMBI penetration which did not prevent β2GPI/anti-β2GPI binding to HUVEC. Surprisingly, β2GPI/anti-β2GPI did not activate ECs harboring EMBI, illustrated by prevention of E-selectin and tissue factor (TF) expression. The inhibition of TF mRNA transcription was illustrated by quantitative RT-PCR. EMBI decreased the expression of phosphorylated JNK1/2, p38, HSP27 and enhanced phosphorylation of glycogen synthase kinase-3β (pGSK3β). Knocking down the GSK3β expression by siRNA-GSK3β, reduced the TF expression by β2GPI/anti-β2GPI-exposed-HUVEC. In-vivo, EMBI significantly decreased the percentage of fetal loss in naïve mice infused with anti-β2GPI Abs, p<0.04. Thus, the dual activity of EMBI may introduce EMBI as a potential novel candidate peptide, to treat patients with APS.
authors.affiliation: Zabludowicz Center for Autoimmune Diseases, Sackler Faculty of Medicine, Tel-Aviv University, Israel.
authors.forename: Miri
authors.initials: M
authors.lastname: Blank
authors.forename: Liran
authors.initials: L
authors.lastname: Baraam
authors.forename: Miriam
authors.initials: M
authors.lastname: Eisenstein
authors.forename: Mati
authors.initials: M
authors.lastname: Fridkin
authors.forename: Rima
authors.initials: R
authors.lastname: Dardik
authors.forename: Yehudit
authors.initials: Y
authors.lastname: Heldman
authors.forename: Ephraim
authors.initials: E
authors.lastname: Katchalski-Katzir
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Shoenfeld
mesh_terms: D000818:Animals; D017152:Antibodies, Antiphospholipid / Q000276:immunology / Q000378:metabolism; D016736:Antiphospholipid Syndrome / Q000201:enzymology / Q000503:physiopathology*; D004195:Disease Models, Animal; D019040:E-Selectin / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000494:pharmacology*; D005260:Female; D005313:Fetal Death / Q000276:immunology / Q000517:prevention & control; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects* / Q000276:immunology; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010455:Peptides / Q000138:chemical synthesis / Q000494:pharmacology*; D010743:Phospholipids / Q000276:immunology / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D011487:Protein Conformation; D012333:RNA, Messenger / Q000378:metabolism; D013925:Thromboplastin / Q000235:genetics / Q000378:metabolism*; D053482:beta 2-Glycoprotein I / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology
chemical_list: D017152:Antibodies, Antiphospholipid; D019040:E-Selectin; D004791:Enzyme Inhibitors; D010455:Peptides; D010743:Phospholipids; D012333:RNA, Messenger; D053482:beta 2-Glycoprotein I; D013925:Thromboplastin; D038362:Glycogen Synthase Kinase 3