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Full-Text Articles in Medicine and Health Sciences
Sphingosine-1-Phosphate-Mediated Mobilization Of Hematopoietic Stem/Progenitor Cells During Intravascular Hemolysis Requires Attenuation Of Sdf-1-Cxcr4 Retention Signaling In Bone Marrow, Kasia Mierzejewska, Yuri M. Klyachkin, Janina Ratajczak, Ahmed Abdel-Latif, Magda Kucia, Mariusz Z. Ratajczak
Sphingosine-1-Phosphate-Mediated Mobilization Of Hematopoietic Stem/Progenitor Cells During Intravascular Hemolysis Requires Attenuation Of Sdf-1-Cxcr4 Retention Signaling In Bone Marrow, Kasia Mierzejewska, Yuri M. Klyachkin, Janina Ratajczak, Ahmed Abdel-Latif, Magda Kucia, Mariusz Z. Ratajczak
Saha Cardiovascular Research Center Faculty Publications
Sphingosine-1-phosphate (S1P) is a crucial chemotactic factor in peripheral blood (PB) involved in the mobilization process and egress of hematopoietic stem/progenitor cells (HSPCs) from bone marrow (BM). Since S1P is present at high levels in erythrocytes, one might assume that, by increasing the plasma S1P level, the hemolysis of red blood cells would induce mobilization of HSPCs. To test this assumption, we induced hemolysis in mice by employing phenylhydrazine (PHZ). We observed that doubling the S1P level in PB from damaged erythrocytes induced only a marginally increased level of mobilization. However, if mice were exposed to PHZ together with the …
Hrs Promotes Ubiquitination And Mediates Endosomal Trafficking Of Smoothened In Drosophila Hedgehog Signaling, Jun-Kai Fan, Kai Jiang, Yajuan Liu, Jianhang Jia
Hrs Promotes Ubiquitination And Mediates Endosomal Trafficking Of Smoothened In Drosophila Hedgehog Signaling, Jun-Kai Fan, Kai Jiang, Yajuan Liu, Jianhang Jia
Markey Cancer Center Faculty Publications
In Hedgehog (Hh) signaling, the seven-transmembrane protein Smoothened (Smo) acts as a signal transducer that is regulated by phosphorylation, ubiquitination, and cell surface accumulation. However, it is not clear how Smo cell surface accumulation and intracellular trafficking are regulated. Here, we demonstrate that inactivation of Hrs by deletion or RNAi accumulates Smo in the late endosome that is marked by late endosome markers. Inactivation of Hrs enhances the wing defects caused by dominant-negative Smo. We show that Hrs promotes Smo ubiquitination, deleting the ubiquitin-interacting-motif (UIM) in Hrs abolishes the ability of Hrs to regulate Smo ubiquitination. However, the UIM domain …
Bioactive Lipids And Cationic Antimicrobial Peptides As New Potential Regulators For Trafficking Of Bone Marrow-Derived Stem Cells In Patients With Acute Myocardial Infarction, Anush V. Karapetyan, Yuri M. Klyachkin, Samy Selim, Manjula Sunkara, Khaled M. Ziada, Donald A. Cohen, Ewa K. Zuba-Surma, Janina Ratajczak, Susan S. Smyth, Mariusz Z. Ratajczak, Andrew J. Morris, Ahmed Abdel-Latif
Bioactive Lipids And Cationic Antimicrobial Peptides As New Potential Regulators For Trafficking Of Bone Marrow-Derived Stem Cells In Patients With Acute Myocardial Infarction, Anush V. Karapetyan, Yuri M. Klyachkin, Samy Selim, Manjula Sunkara, Khaled M. Ziada, Donald A. Cohen, Ewa K. Zuba-Surma, Janina Ratajczak, Susan S. Smyth, Mariusz Z. Ratajczak, Andrew J. Morris, Ahmed Abdel-Latif
Internal Medicine Faculty Publications
Acute myocardial infarction (AMI) triggers mobilization of stem cells from bone marrow (BM) into peripheral blood (PB). Based on our observation that the bioactive sphingophospholipids, sphingosine-1 phosphate (S1P), and ceramide-1 phosphate (C1P) regulate trafficking of hematopoietic stem cells (HSCs), we explored whether they also direct trafficking of non-hematopoietic stem cells (non-HSCs). We detected a 3–6-fold increase in circulating CD34+, CD133+, and CXCR4+ lineage-negative (Lin−)/CD45− cells that are enriched in non-HSCs [including endothelial progenitors (EPCs) and very small embryonic-like stem cells (VSELs)] in PB from AMI patients (P<0.05 vs. controls). Concurrently, we measured a 3-fold increase in S1P and C1P levels in plasma from AMI patients. At the same time, plasma obtained at hospital admission and 6 h after AMI strongly chemoattracted human BM-derived CD34+/Lin− and CXCR4+/Lin− cells in Transwell chemotaxis assays. This effect of plasma was blunted after depletion of S1P level by charcoal stripping and was further inhibited by the specific S1P1 receptor antagonist such as W146 and VPC23019. We also noted that the expression of S1P receptor 1 (S1P1), which is dominant in naïve BM, is reduced after the exposure to S1P at concentrations similar to the plasma S1P levels in patients with AMI, thus influencing the role of S1P in homing to the injured myocardium. Therefore, we examined mechanisms, other than bioactive lipids, that may contribute to the homing of BM non-HSCs to the infarcted myocardium. Hypoxic cardiac tissue increases the expression of cathelicidin and β-2 defensin, which could explain why PB cells isolated from patients with AMI migrated more efficiently to a low, yet physiological, gradient of stromal-derived factor-1 in Transwell migration assays. Together, these observations suggest that while elevated S1P and C1P levels early in the course of AMI may trigger mobilization of non-HSCs into PB, cathelicidin and β-2 defensin could play an important role in their homing to damaged myocardium.