Type I and type II interferons delay human neutrophil apoptosis via activation of STAT3 and up-regulation of cellular inhibitor of apoptosis 2.

We have recently demonstrated that granulocyte-colony stimulating factor (G-CSF) delays human neutrophil apoptosis via up-regulation of cellular inhibitor of apoptosis 2 (cIAP2), which is dependent on activation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3). Here, we show that type I and type II interferons (IFNs), which bind to the distinct receptors, exert the antiapoptotic effect on human neutrophils through the similar mechanism. IFN-alpha (type I IFN) and IFN-gamma (type II IFN), like G-CSF, delayed human neutrophil apoptosis through the protein synthesis-dependent mechanism. Stimulation of neutrophils with IFN-alpha or IFN-gamma resulted in tyrosine phosphorylation of STAT1 and STAT3 but not phosphorylation of STAT5, Akt, extracellular signal-regulated kinase, and p38 mitogen-activated protein kinase. IFN-alpha and IFN-gamma induced the expression of transcripts of cIAP2 and suppressor of cytokine signaling 1 and 3, but not cIAP1, Mcl-1, and A1. IFN-alpha- and IFN-gamma-induced up-regulation of cIAP2 mRNA and protein, phosphorylation of STAT3, and antiapoptotic effect were inhibited significantly by pretreatment of cells with AG490, a specific inhibitor of JAK2. These findings suggest that cIAP2 expression is up-regulated by IFN-alpha and IFN-gamma through, at least in part, activation of the JAK2-STAT3 pathway, and increased expression of the cIAP2 protein may contribute to an IFN-alpha- and IFN-gamma-mediated antiapoptotic effect on human neutrophils.

Antiapoptotic effect of granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, and cyclic AMP on human neutrophils: protein synthesis-dependent and protein synthesis-independent mechanisms and the role of the Janus kinase-STAT pathway.

Spontaneous neutrophil apoptosis during culture was delayed by granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF), or dibutyryl-cyclic adenosine monophosphate (cAMP), whereas apoptosis was accelerated by cycloheximide or actinomycin D. G-CSF-mediated antiapoptosis was completely abolished by cycloheximide or actinomycin D, whereas GM-CSF-mediated antiapoptosis was not completely abolished by these inhibitors. Antiapoptosis induced by dibutyryl-cAMP was highly resistant to cycloheximide, and that induced by benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone was unaffected by cycloheximide. G-CSF- and GM-CSF-mediated antiapoptosis and phosphorylation of signal transducer and activator of transcription 3 (STAT3) and STAT5 were inhibited by AG490, an inhibitor of Janus kinase. The level of Mcl-1 protein was not associated with neutrophil apoptosis. The results suggest that (a) neutrophil survival in the resting state is primarily regulated by the constitutive synthesis of antiapoptotic proteins; (b) the prevention of spontaneous apoptosis is mediated through the protein synthesis-dependent and/or protein synthesis-independent mechanisms according to the stimuli used; and (c) the Janus kinase-STAT pathway is involved in G-CSF- and GM-CSF-mediated antiapoptosis.

QT dispersion correlates with systolic rather than diastolic parameters in patients receiving anthracycline treatment.

OBJECTIVE: The aim of this study was to investigate the relation of QT dispersion to left ventricular (LV) systolic and diastolic function in patients undergoing anthracycline therapy. METHODS: We used echocardiography to evaluate LV systolic and diastolic function and electrocardiography to evaluate QT dispersion and corrected QT dispersion (QTcD) in patients with hematological diseases, who received anthracycline therapy. PATIENTS: Seventy-two patients with hematological diseases who were receiving anthracycline treatment were enrolled in the present study. RESULTS: LV end-diastolic diameter or LV end-systolic diameter had a significant positive correlation to QTcD (r = 0.35, p < 0.01, r = 0.43, p < 0.01). Also left ventricular ejection fraction of (LVEF) or fractional shortening had a significant negative correlation to QTcD (r = -0.46, p < 0.001, r = -0.27, p = 0.02). The highest QTcD group had a significantly larger LV end-diastolic diameter or LV end-systolic diameter than the lowest QTcD [48.5 +/- 5.7 vs. 44.4 +/- 4.5 (mm), p < 0.001, 34.1 +/- 6.4 vs. 28.8 +/- 4.3 (mm), p < 0.001] and the highest QTcD group had a significantly lower LVEF than the lowest QTcD [57.5 +/- 8.0 vs. 65.5 +/- 6.4 (%), p < 0.001]. On the other hand, none of the diastolic function markers were significantly correlated with QTcD. CONCLUSION: We concluded that increased QTcD is correlated with LV dilation and systolic dysfunction induced by anthracycline therapy, and does not reflect a dispersion of ventricular repolarization or asynchronous motion.

Enhanced neutrophil motility by granulocyte colony-stimulating factor: the role of extracellular signal-regulated kinase and phosphatidylinositol 3-kinase.

The effect of granulocyte colony-stimulating factor (G-CSF) on human neutrophil motility was studied using videomicroscopy. Stimulation of neutrophils with G-CSF resulted in enhanced motility with morphological change and increased adherence. Enhanced neutrophil motility was detected within 3-5 min after G-CSF stimulation, reached a maximum at 10 min, and was sustained for approximately 35 min. The maximum migration rate was 84.4 +/- 2.9 microm/5 min. A study using the Boyden chamber method revealed that G-CSF-stimulated neutrophils exhibited random migration but not chemotaxis. Enhanced neutrophil motility and morphological change were inhibited by MEK [mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase] inhibitors (PD98059 and U0126), and a phosphatidylinositol 3-kinase (PI3K) inhibitor (wortmannin), but not by a p38 MAPK inhibitor (SB203580). These findings are consistent with the fact that G-CSF selectively activates MEK/ERK and PI3K, but not p38, in neutrophils. MEK/ERK activation was associated with G-CSF-induced redistribution of F-actin and phosphorylated myosin light chain. Enhanced neutrophil motility was observed even in the presence of neutralizing anti-CD18 antibody, which prevented cell adherence. These findings indicate that G-CSF induces human neutrophil migration via activation of MEK/ERK and PI3K.

Predictive value of QT dispersion for acute heart failure after autologous and allogeneic hematopoietic stem cell transplantation.

The aim of our study was to evaluate whether corrected QT dispersion (QTc dispersion), an electrocardiographic marker, is a good predictor of the development of acute heart failure after high-dose chemotherapy followed by autologous or allogeneic hematopoietic stem cell transplantation. We enrolled 50 consecutive patients, from age 15 to 63 years, with hematopoietic diseases scheduled to undergo autologous or allogeneic hematopoietic stem cell transplantation, and compared QTc dispersion with other markers before transplantation conditioning. In univariate logistic analysis, QTc dispersion was a significant factor for acute heart failure after hematopoietic stem cell transplantation (odds ratio, 3.7 per 10 msec; confidence interval, 1.6-8.5; P = 0.002). There were no significant differences as age, sex, systolic or diastolic echocardiographic function markers, cumulative anthracycline dose, or QTc before transplantation between patients with and without acute heart failure. After multiple adjustments for left ventricular ejection fraction, cumulative anthracycline dose, cyclophosphamide conditioning dose, QTc dispersion was a significant and independent factor for acute heart failure after hematopoietic stem cell transplantation (odds ratio, 48.0 per 10 msec; confidence interval, 1.4-1666.3; P = 0.03). This study demonstrated that QTc dispersion could be used as a powerful noninvasive predictor of the development of acute heart failure after hematopoietic stem cell transplantation.