Thrombopoietin (TPO), acting through its receptor Mpl, has two major physiological roles: ensuring production of sufficient platelets via stimulation of megakaryocyte production and maintaining hematopoietic stem cell (HSC) quiescence. Mpl also controls circulating TPO concentration via receptor-mediated internalization and degradation. Here, we demonstrate that the megakaryocytosis and increas...

Thyroid peroxidase (TPO) autoantibody epitopes are largely restricted to an immunodominant region (IDR) on the extracellular region of the native molecule. Localization of the IDR has been a longstanding and difficult goal. The TPO extracellular region comprises a large myeloperoxidase-like domain, linked to the plasma membrane by two smaller domains with homology to complement control protein ...

model. To compare the translational efficiencies of normal and mutant TPO mRNAs, the DG mutation was introduced into the 58-UTR of TPO cDNA by recombinant polymerase chain reaction (PCR) and subcloned into the pcDNA3 vector, as previously described.2 Mutant and control TPO mRNAs were transcribed in vitro using T7 polymerase and translated in reticulocyte lysate in the presence of 35S-methionine...

Little is known about the behaviour of endogenous thrombopoietin (TPO) serum levels during rapid sequences of dose-intensified chemotherapy. To characterize the relationship between TPO levels and platelet counts in this setting we serially measured both parameters over the entire treatment period of patients receiving multicycle polychemotherapy. We found TPO and platelet responses to be gener...

Severe suppression of the hematopoietic system is a major factor in limiting chemotherapy dose escalation. To determine whether a combination of human recombinant granulocyte colony-stimulating factor (G-CSF) and thrombopoietin (TPO) would alter recovery of platelets, red blood cells (RBCs), or neutrophils after myeloablative therapy, myelosuppressed mice were treated with sc injections of TPO ...

Thrombopoietin (TPO) and its receptor (TPOR) are expressed in the central nervous system (CNS). Although TPO shares significant homology with various neurotrophins, recent data indicate a proapoptotic function of TPO in the CNS. In this study, TPO concentrations were analyzed in the cerebrospinal fluid (CSF) of neonates. Human neuroblastoma-derived SH-SY5Y cells were established to elucidate th...

The involvement of platelets and the c-mpl receptor in the regulation of thrombopoietin (TPO) plasma concentrations and tissue mRNA levels was investigated in both normal mice and mice defective in c-mpl (c-mpl-/-). Although c-mpl-/- mice have fewer platelets and higher plasma TPO activity than normal mice, there was no increase in TPO mRNA levels as measured by an S1 nuclease protection assay....

OBJECTIVE We have previously reported that the absence of thyroid peroxidase antibodies (TPOAb) in Graves' disease (GD) was associated with an increased risk of Graves' ophthalmopathy (GO). This observation raised the possibility that TPOAb could act as a protective factor. However, the presence of thyroid peroxidase (TPO) in the orbit has not been previously reported. The aim of this study was...

The function of bone marrow (BM) stromal thrombopoietin (TPO) in megakaryopoiesis remains unknown. In the present study we attempted to clarify the pathophysiological implications of stromal TPO in normal subjects (NS) and in patients with idiopathic thrombocytopenic purpura (ITP), aplastic anemia (AA), and essential thrombocythemia (ET) by measuring TPO concentrations in BM and peripheral bloo...