A donor-specific QTL, exhibiting allelic variation for leaf sheath hairiness in a nested association mapping population, is located on barley chromosome 4H.

Leaf sheath hairiness is a morphological trait associated with various advantages, including tolerance to both abiotic and biotic stresses, thereby increasing yield. Understanding the genetic basis of this trait in barley can therefore improve the agronomic performance of this economically important crop. We scored leaf sheath hairiness in a two-year field trial in 1,420 BC1S3 lines from the wild barley nested association mapping (NAM) population HEB-25. Leaf sheath hairiness segregated in six out of 25 families with the reference parent Barke being glabrous. We detected the major hairy leaf sheath locus Hs (syn. Hsh) on chromosome 4H (111.3 cM) with high precision. The effects of the locus varied across the six different wild barley donors, with donor of HEB family 11 conferring the highest score of leaf sheath hairiness. Due to the high mapping resolution present in HEB-25, we were able to discuss physically linked pentatricopeptide repeat genes and subtilisin-like proteases as potential candidate genes underlying this locus. In this study, we proved that HEB-25 provides an appropriate tool to further understand the genetic control of leaf sheath hairiness in barley. Furthermore, our work represents a perfect starting position to clone the gene responsible for the 4H locus observed.

Budesonide added to formoterol contributes to improved exercise tolerance in patients with COPD.

BACKGROUND: Breathlessness and exercise intolerance frequently impact the daily life of patients with COPD. METHODS: This double-blind, multicentre, three-period crossover study randomised 111 patients with COPD (mean age 64 years, mean FEV(1) 38% of predicted normal) to budesonide/formoterol 320/9 microg, formoterol 9 microg or placebo, twice daily for 1 week, following a 1-week run-in period with 1-week wash-out between treatments. Terbutaline (0.5 mg/dose) was used as needed. The primary efficacy variable was exercise endurance time (EET) at 75% peak work capacity with cycle ergometry assessed 1 h post-morning dose. RESULTS: Budesonide/formoterol prolonged EET 1 h post-morning dose versus formoterol by 69 s (P < 0.005) and placebo by 105 s (P < 0.0001) and improved inspiratory capacity (IC) at isotime during exercise versus formoterol by 8% (P = 0.011) and placebo by 16% (P < 0.0001). Borg score at isotime was reduced by 0.48 (P = 0.12) and 0.78 (P = 0.014) compared with formoterol and placebo, respectively. At the repeated cycle test 6 h after morning dose, the effect on EET still favoured budesonide/formoterol over formoterol and placebo, while the isotime IC and Borg score were similar but better than placebo for the active study drugs. Budesonide/formoterol and formoterol improved health status (St George's Respiratory Questionnaire total score: mean difference versus placebo -2.4 and -2.2, respectively). All treatments were well tolerated. CONCLUSIONS: Budesonide/formoterol resulted in a significant improvement in endurance time 1 h after the last morning dose in a 1-week treatment period versus formoterol and placebo. This study demonstrates, for the first time, the benefit of inhaled corticosteroids in addition to long-acting beta(2)-agonists on exercise tolerance in COPD patients. www.clinicaltrials.gov registration number: NCT00489853.

Role of p21(WAF1/CIP1) as an attenuator of both proliferative and drug-induced apoptotic signals in BCR-ABL-transformed hematopoietic cells.

The constitutive tyrosine kinase activity of the BCR-ABL fusion protein plays a crucial role in the pathogenesis of chronic myeloid leukemia and promotes growth factor-independent survival of hematopoietic cells. In 32D cells, expression levels of retrovirally transduced BCR-ABL were positively correlated with the levels of the cell cycle regulator protein p21, and this upregulation of p21 expression depended on the kinase activity of BCR-ABL. To assess the role of p21 on BCR-ABL-positive hematopoietic cells, we compared proliferation and drug-induced apoptosis in bone marrow (BM) cells from wild-type and p21 knockout mice after retroviral transfer of the BCR-ABL fusion gene. As compared with wild-type cells, p21 knockout cells showed increased proliferation, suggesting that p21 acted as an attenuator of BCR-ABL-mediated cell proliferation. In marked contrast, deletion of p21 promoted apoptosis induction by imatinib and taxol in BCR-ABL-transformed BM cells. These findings demonstrate that p21 has a dual function in BCR-ABL-transformed murine BM cells: It attenuates the effects of two apparently opposed phenomena such as BCR-ABL-mediated cell proliferation and drug-induced apoptosis. This dual function of p21 calls for a cautious evaluation of the suitability of p21 as a secondary target in anticancer therapy.

Dual-specific Src and Abl kinase inhibitors, PP1 and CGP76030, inhibit growth and survival of cells expressing imatinib mesylate-resistant Bcr-Abl kinases.

The leukemogenic tyrosine kinase Bcr-Abl contains a highly conserved inhibitor-binding pocket (IBP), which serves as a binding site for imatinib mesylate. Mutations at the IBP may lead to resistance of the Abl kinase against imatinib mesylate. To examine the mechanisms of imatinib mesylate binding and resistance in more detail, we created several point mutations at amino acid positions 315 and 380 of Abl, blocking the access to the IBP and rendering Bcr-Abl imatinib mesylate-resistant. Moreover, introduction of a mutation destabilizing the inactive conformation of Abl (Asp276Ser/Glu279Ser) also led to imatinib mesylate resistance, suggesting that the inhibitor required inactivation of the kinase prior to binding. These Bcr-Abl mutants were then used to evaluate the binding mode and specificity of 2 compounds, PP1 and CGP76030, originally characterized as Src kinase inhibitors. Both compounds inhibited Bcr-Abl in a concentration-dependent manner by overlapping binding modes. However, in contrast to imatinib mesylate, PP1 and CGP76030 blocked cell growth and survival in cells expressing various inhibitor-resistant Abl mutants. Studies on the potential signaling mechanisms demonstrated that in cells expressing inhibitor-resistant Bcr-Abl mutants, PP1 and CGP76030 inhibited the activity of Src family tyrosine kinases and Akt but not signal transducer and activator of transcription-5 (STAT5) and JUN kinase (Jnk). The results suggest that the use of Src kinase inhibitors is a potential strategy to prevent or overcome clonal evolution of imatinib mesylate resistance in Bcr-Abl(+) leukemia.

The effects of Bcr-Abl on C/EBP transcription-factor regulation and neutrophilic differentiation are reversed by the Abl kinase inhibitor imatinib mesylate.

The clinical progression of chronic myeloid leukemia (CML) from chronic phase to blast crisis is characterized by the increasing failure of myeloid precursors to differentiate into mature granulocytes. This study was undertaken to investigate the influence of Bcr-Abl and of the small molecule Abl tyrosine-kinase inhibitor imatinib mesylate on granulocyte colony-stimulating factor (G-CSF)-induced neutrophilic differentiation. We show that differentiation of 32Dcl3 cells into mature granulocytes is accompanied by the increased expression of the antigens macrophage adhesion molecule-1 (Mac-1) and Gr-1, of the G-CSF receptor (G-CSFR), of myeloid transcription factors (CCAAT/enhancer-binding protein-alpha [C/EBPalpha], C/EBPepsilon, and PU.1), and of the cyclin-dependent kinase inhibitor p27(Kip1). In 32Dcl3 cells transfected with the bcr-abl gene (32D(Bcr-Abl)), G-CSF did not trigger either granulocytic differentiation or the up-regulation of C/EBPalpha, C/EBPepsilon, and the G-CSFR. This could be correlated to a defect in c-Myc down-regulation. In contrast, the up-regulation of PU.1 and p27(Kip1) by G-CSF was not affected by Bcr-Abl. Importantly, incubation of 32D(Bcr-Ablwt) cells with the kinase inhibitor imatinib mesylate prior to G-CSF stimulation completely neutralized the effects of Bcr-Abl on granulocytic differentiation and on C/EBPalpha and C/EBPepsilon expression. Taken together, the results suggest that the Bcr-Abl kinase induces a reversible block of the granulocytic differentiation program in myeloid cells by disturbing regulation of hematopoietic transcription factors such as C/EBPalpha and C/EBPepsilon.