BACKGROUND Despite being a high burden disorder, the pathogenesis of severe refractory asthma (SRA) is poorly understood. There are some evidences for the involvement of members of the signal transducer and activator of transcription (STAT) family, including STAT3 and STAT5a. Our study aimed to evaluate the gene expression of STAT3 and STAT5a in asthma and SRA to establish if there is an associ...

Signal transducer and activator of transcription (Stat)5a and Stat5b are critical for normal immune function. Progression of T cells through G(1)-S phase of cell cycle requires T cell receptor (TCR)- and/or cytokine-inducible tyrosine phosphorylation of Stat5a/b. Stat5a/b may also, in a cell-dependent manner, be constitutively or cytokine-inducibly phosphorylated on a Pro-Ser-Pro (PSP) motif lo...

Stats (signal transducers and activators of transcription) regulate multiple aspects of T-cell fate. T regulatory (Treg) cells are a critical subset that limits immune responses, but the relative importance of Stat5a/b versus Stat3 for Treg cell development has been contentious. We observed that peripheral CD25(+)CD4(+) T cells were reduced in Stat5(DeltaN) mice; however, the levels of Foxp3, a...

STAT5 proteins are constitutively activated in malignant cells from many patients with leukemia, including the myeloproliferative neoplasms (MPNs) chronic myeloid leukemia (CML) and polycythemia vera (PV), but whether STAT5 is essential for the pathogenesis of these diseases is not known. In the present study, we used mice with a conditional null mutation in the Stat5a/b gene locus to determine...

We have defined the optimal binding sites for Stat5a and Stat5b homodimers and found that they share similar core TTC(T/C)N(G/A)GAA interferon gamma-activated sequence (GAS) motifs. Stat5a tetramers can bind to tandemly linked GAS motifs, but the binding site selection revealed that tetrameric binding also can be seen with a wide range of nonconsensus motifs, which in many cases did not allow S...

We analysed STAT5A gene expression in breast cancer using the Oncomine database. We exemplify four representative studies showing that STAT5A is generally downregulated in breast cancer.

Previously, we demonstrated that enforced activation of signal transducer and activator of transcription 5 (STAT5A) in human cord blood (CB)-derived stem/progenitor cells results in enhanced self-renewal and impaired myelopoiesis. The present study identifies C/EBPalpha as a critical component that is down-regulated by STAT5. Microarray and reverse transcriptase-polymerase chain reaction (RT-PC...

The cytokines interleukin 7 (IL-7) and interleukin 4 (IL-4) regulate lymphoid differentiation and function and activate the transcription factor Stat5. Using mice deficient for the 2 highly related transcription factors, Stat5a and Stat5b (Stat5a/b(-/-)), we investigated the role of Stat5 for B-cell differentiation, expansion, and function. Peripheral blood B cells of Stat5-deficient mice are s...

The lactogenic hormones, i.e., prolactin and glucocorticoids, act in concert to stimulate transcription factors responsible for hormone-dependent milk protein gene expression. In the mammary gland, prolactin activates Stat5a and Stat5b and glucocorticoids activate the glucocorticoid receptor (GR). Immunoprecipitation experiments revealed that in mammary cells, Stat5a, Stat5b, and the GR are phy...

The mammary gland undergoes extensive tissue remodeling and cell death at the end of lactation in a process known as involution. We present evidence that the prolactin-activated transcription factor signal transducer and activator of transcription 5a (Stat5a) has a crucial role in the regulation of cell death during mammary gland involution. In a transforming growth factor-alpha transgenic mous...