BACKGROUND Thyroperoxidase (TPO) is a membrane-bound protein essential for the production of thyroid hormones; because of this, TPO expression may be impaired in selected thyroid diseases. The goal of this study is to analyze TPO immune expression in differentiated thyroid cancer, and to determine whether TPO has any prognostic value. METHODS A total of 139 patients who required surgery due t...

BACKGROUND Chronic spontaneous urticaria (csU), which is characterized by recurrent episodes of mast cell-driven wheal and flare-type skin reactions, is often associated with elevated total IgE levels and thyroid autoimmunity. We speculate that some csU patients express IgE autoantibodies against thyroid antigens such as thyroid peroxidase (TPO), which could bind to skin mast cells and induce t...

AIMS Thrombopoietin (Tpo) is known for its ability to stimulate platelet production. However, it is currently unknown whether Tpo plays a physiological function in the heart. METHODS AND RESULTS We assessed the potential protective role of Tpo in vitro and in vivo in two rat models of myocardial ischaemia/reperfusion. Tpo receptor (c-mpl) message was detected in the heart using RT-PCR, and th...

Thrombopoietin (Tpo), the ligand for c-mpl, has been shown to be the principal regulator of megakaryocytopoiesis and platelet production. The ability of Tpo to potently stimulate the growth of committed megakaryocyte (Mk) progenitor cells has been studied in detail. Murine fetal liver cells, highly enriched in primitive progenitors, have been shown to express c-mpl, but little is known about th...

Thrombopoietin (TPO) is the primary hematopoietic growth factor involved in the regulation of platelet production. Although the kidney, liver, bone marrow (BM), and spleen have been identified as the major sources of TPO production, the precise cellular location of TPO mRNA expression in these tissues remains unknown. We have identified the cells expressing TPO mRNA in the human kidney, liver, ...

Hashimoto's thyroiditis, a common autoimmune disease, is associated with autoantibodies to thyroglobulin (Tg) and thyroid peroxidase (TPO). TPO, unlike abundant and easily purified Tg, is rarely investigated as an autoantigen in animals. We asked whether antibodies (Abs) develop to both TPO and Tg in thyroiditis that is induced (C57BL/6 and DBA/1 mice) or arises spontaneously (NOD.H-2h4 mice). ...

Thrombopoietin (TPO) is a recently identified growth factor that regulates megakaryocytopoiesis. Its receptor, c-Mpl, is expressed in megakaryocyte progenitors, mature megakaryocytes, and human blood platelets. We have observed that TPO treatment of human platelets resulted in tyrosine phosphorylation of several cellular proteins, including the c-Mpl receptor and the 85-kD subunit of phosphatid...

Thrombopoietin (TPO) has recently been cloned and shown to regulate megakaryocyte and platelet production by activating the cytokine receptor c-mpl. To determine whether TPO is the only ligand for c-mpl and the major regulator of megakaryocytopoiesis, TPO deficient mice were generated by gene targeting. TPO-/-mice have a >80% decrease in their platelets and megakaryocytes but have normal levels...

BACKGROUND Thyroid peroxidase (TPO) is essential for physiological function of the thyroid gland. The high prevalence of thyroid peroxidase antibodies (TPOAbs) in patients with breast cancer and their protective role had previously been demonstrated, indicating a link between breast cancer and thyroid autoimmunity. Recently, TPO was shown to be present in breast cancer tissue samples but its an...

A full-length cDNA clone for human thyroid peroxidase (TPO) inserted into the mammalian cell expression vector pECE was stably transfected into Chinese hamster ovary (CHO) cells. Clones were assayed for human TPO mRNA, TPO protein, and TPO enzymatic activity. One subclone, expressing the highest TPO enzymatic activity, was used in further studies. FACS analysis of these cells preincubated in Ha...