Heme-regulated eIF2α kinase activated Atf4 signaling pathway in oxidative stress and erythropoiesis.

Heme-regulated eIF2α kinase (Hri) is necessary for balanced synthesis of heme and globin. In addition, Hri deficiency exacerbates the phenotypic severity of ß-thalassemia intermedia in mice. Activation of Hri during heme deficiency and in ß-thalassemia increases eIF2α phosphorylation and inhibits globin translation. Under endoplasmic reticulum stress and nutrient starvation, eIF2α phosphorylation also induces the Atf4 signaling pathway to mitigate stress. Although the function of Hri in regulating globin translation is well established, its role in Atf4 signaling in erythroid precursors is not known. Here, we report the role of the Hri-activated Atf4 signaling pathway in reducing oxidative stress and in promoting erythroid differentiation during erythropoiesis. On acute oxidative stress, Hri(-/-) erythroblasts suffered from increased levels of reactive oxygen species (ROS) and apoptosis. During chronic iron deficiency in vivo, Hri is necessary both to reduce oxidative stress and to promote erythroid differentiation. Hri(-/-) mice developed ineffective erythropoiesis during iron deficiency with inhibition of differentiation at the basophilic erythroblast stage. This inhibition is recapitulated during ex vivo differentiation of Hri(-/-) fetal liver erythroid progenitors. Importantly, the Hri-eIF2αP-Atf4 pathway was activated and required for erythroid differentiation. We further demonstrate the potential of modulating Hri-eIF2αP-Atf4 signaling with chemical compounds as pharmaceutical therapies for ß-thalassemia.

Moving the needle: Quality improvement strategies to achieve guideline-concordant care of obstetric patients with severe hypertension.

OBJECTIVES: To improve timely treatment and follow-up of birthing individuals with severe hypertension. STUDY DESIGN: A quality improvement (QI) initiative was implemented at an academic tertiary care center in the United States of America for individuals with obstetric hypertensive emergencies. Statistical process control charts were utilized to track process measures and interventions tested through plan-do-study-act cycles. Measures were disaggregated by race and ethnicity to identify and improve disparities. MAIN OUTCOME MEASURES: Treatment of hypertensive events within 60 min, receipt of blood pressure (BP) device at discharge and completed postpartum follow-up BP check within 7 days of discharge. RESULTS: All process measures showed statistically significant improvements. The primary process measure, timely treatment of hypertensive emergencies, improved from 29 % to 76 %. Receipt of BP device improved from 37 % to 91 % and follow-up BP checks from 58 % to 81 %. No racial or ethnic disparities were noted at baseline or after interventions. Readmission rates within 6 weeks of delivery increased from 2.3 % to 6.1 % for the cohort with no severe morbidity or mortality events after discharge. Strategies associated with improvement included project launch with establishment of the "why," telehealth, simulation, a video display of quality metrics on the birthing unit, promoting BP cuff access, and automated orders. CONCLUSIONS: This comprehensive QI initiative provides novel improvement strategies for the management of individuals with severe hypertensive disorders of pregnancy for the timely treatment of severe BP, attainment of home BP devices, and follow-up after discharge. Quality improvement methodology is practical and essential for achieving guideline-concordant care.

Molecular magnetic resonance imaging of pulmonary fibrosis in mice.

Idiopathic pulmonary fibrosis is a chronic, progressive, fibrosing interstitial pneumonia of unknown cause resulting in dyspnea and functional decline until death. There are currently no effective noninvasive tools to monitor disease progression and response to treatment. The objective of the present study was to determine whether molecular magnetic resonance imaging of the lung using a probe targeted to type I collagen could provide a direct, noninvasive method for assessment of pulmonary fibrosis in a mouse model. Pulmonary fibrosis was generated in mice by transtracheal instillation of bleomycin (BM). Six cohorts were imaged before and immediately after intravenous administration of molecular imaging probe: (1) BM plus collagen-targeted probe, EP-3533; (2) sham plus EP-3533; (3) BM plus nonbinding control probe, EP-3612; (4) sham plus EP-3612; (5) BM plus EP-3533 imaged early; and (6) BM plus EP-3533 imaged late. Signal-to-noise ratio (SNR) enhancement was quantified in the lungs and muscle. Lung tissue was subjected to pathologic scoring of fibrosis and analyzed for gadolinium and hydroxyproline. BM-treated mice had 35% higher lung collagen than sham mice (P < 0.0001). The SNR increase in the lungs of fibrotic mice after EP-3533 administration was twofold higher than in sham animals and twofold higher than in fibrotic or sham mice that received control probe, EP-3612 (P < 0.0001). The SNR increase in muscle was similar for all cohorts. For EP-3533, we observed a strong, positive, linear correlation between lung SNR increase and hydroxyproline levels (r = 0.72). Collagen-targeted probe EP-3533-enhanced magnetic resonance imaging specifically detects pulmonary fibrosis in a mouse model of disease.

CCAAT/enhancer-binding protein-beta participates in insulin-responsive expression of the factor VII gene.

Expression of the human coagulation factor VII (FVII) gene by hepatoma cells was modulated in concert with levels of glucose and insulin in the culture medium. In low glucose medium without insulin, amounts of both FVII mRNA and secreted FVII protein were coordinately increased; in the presence of glucose with insulin, both were decreased. Analysis of the FVII promoter showed that these effects could be reproduced in a reporter-gene system, and a small promoter element immediately upstream of the translation start site of the gene, which mediated these effects, was identified. Mutation of this element largely abrogated the glucose/insulin-responsive change in expression of the reporter gene. Several members of the CCAAT/enhancer-binding protein family were found to be capable of binding the identified sequence element but not the mutated element. The expression of a FVII minigene directed by a segment of the native FVII promoter responded to co-expressed activating and inhibiting forms of CCAAT/enhancer-binding protein beta.