Effects of Stem Cell Factor on Hypoxia-Inducible Factor 1 Alpha Accumulation in Human Acute Myeloid Leukaemia and LAD2 Mast Cells

Stem cell factor (SCF) is a hematopoietic growth factor that exerts its activity by signalling through the tyrosine kinase receptor known as Kit or CD117. SCF-Kit signalling is crucial for the survival, proliferation and differentiation of hematopoietic cells of myeloid lineage. Furthermore, since myeloid leukaemia cells express the Kit receptor, SCF may play an important role in myeloid leukaemia progression too. However, the mechanisms of this pathophysiological effect remain unclear. Recent evidence shows that SCF triggers accumulation of the inducible alpha subunit of hypoxia-inducible factor 1 (HIF-1) in hematopoietic cells—a transcription complex that plays a pivotal role in cellular adaptation to low oxygen availability. However, it is unknown how SCF impacts on HIF-1α accumulation in human myeloid leukaemia and mast cells. Here we show that SCF induces HIF-1α accumulation in THP-1 human myeloid leukaemia cells but not in LAD2 mast cells. We demonstrated that LAD2 cells have a more robust glutathione (GSH)-dependent antioxidative system compared to THP-1 cells and are therefore protected against the actions of ROS generated in an SCF-dependent manner. BSO-induced GSH depletion led to a significant decrease in HIF-1α prolyl hydroxylase (PHD) activity in THP-1 cells and to near attenuation of it in LAD2 cells. In THP-1 cells, SCF-induced HIF-1α accumulation is controlled via ERK, PI3 kinase/PKC-δ/mTOR-dependent and to a certain extent by redox-dependent mechanisms. These results demonstrate for the first time an important cross-talk of signalling pathways associated with HIF-1 activation—an important stage of the myeloid leukaemia cell life cycle

Plasma proteins elevated in severe asthma despite oral steroid use and unrelated to Type-2 inflammation

Rationale Asthma phenotyping requires novel biomarker discovery. Objectives To identify plasma biomarkers associated with asthma phenotypes by application of a new proteomic panel to samples from two well-characterised cohorts of severe (SA) and mild-to-moderate (MMA) asthmatics, COPD subjects and healthy controls (HCs). Methods An antibody-based array targeting 177 proteins predominantly involved in pathways relevant to inflammation, lipid metabolism, signal transduction and extracellular matrix was applied to plasma from 525 asthmatics and HCs in the U-BIOPRED cohort, and 142 subjects with asthma and COPD from the validation cohort BIOAIR. Effects of oral corticosteroids (OCS) were determined by a 2-week, placebo-controlled OCS trial in BIOAIR, and confirmed by relation to objective OCS measures in U-BIOPRED. Results In U-BIOPRED, 110 proteins were significantly different, mostly elevated, in SA compared to MMA and HCs. 10 proteins were elevated in SA versus MMA in both U-BIOPRED and BIOAIR (alpha-1-antichymotrypsin, apolipoprotein-E, complement component 9, complement factor I, macrophage inflammatory protein-3, interleukin-6, sphingomyelin phosphodiesterase 3, TNF receptor superfamily member 11a, transforming growth factor-β and glutathione S-transferase). OCS treatment decreased most proteins, yet differences between SA and MMA remained following correction for OCS use. Consensus clustering of U-BIOPRED protein data yielded six clusters associated with asthma control, quality of life, blood neutrophils, high-sensitivity C-reactive protein and body mass index, but not Type-2 inflammatory biomarkers. The mast cell specific enzyme carboxypeptidase A3 was one major contributor to cluster differentiation. Conclusions The plasma proteomic panel revealed previously unexplored yet potentially useful Type-2independent biomarkers and validated several proteins with established involvement in the pathophysiology of SA

ВПЛИВ РЕТИНО-ГІПОТАЛАМО-ЕПІФІЗАРНОЇ СИСТЕМИ НА ПРОТЕОЛІЗ У ТКАНИНАХ ЯСЕН У СТАТЕВОЗРІЛИХ САМЦІВ ЩУРІВ

Abstract. Experimentally in adult male albino rats under constant light or constant darkness for 14 days and intermittent hypobaric hypoxia (2 h. daily) the specific features of changes of proteolytic activity were observed in the gingival tissue of experimental animals. Permanent lighting did not change the activity of proteolysis of low and high molecular weight proteins, but increased the intensity of the lysis of collagen by 20,57%. The opposite effect on proteolytic processes had darkness. Under the influence of constant darkness lysis of low molecular weight proteins decreased by 25,80%, high molecular weight – 19,04% and 24,47% collagen. Hypoxia and natural light reduced the lysis of the proteins which we staded. The combined effect of hypoxia and constant light caused decrease the lysis of staded proteins in comparison with the effect of only lighting. The combined effect of hypoxia and constant darkness had more pronounced effect: the lysis of low molecular weight proteins decreased by 21,89%, high molecular weight proteins by 30,52% and 67,61% on collagen compared with the effect of only one darkness.Резюме. Экспериментально на половозрелых самцах белых крыс под действием постоянного освещения или постоянной темноты в течение 14 суток и прерывистой гипобарической гипоксии (2 час. в сутки) установлены особенности изменений протеолитической активности в тканях десен подопытных животных. Постоянное освещение не изменило активности протеолиза низко- и высокомолекулярных белков, но повысило интенсивность лизиса коллагена на 20,57%. Противоположный эффект на протеолитические процессы имела темнота. Под влиянием постоянной темноты лизис низкомолекулярных белков уменьшился на 25,80%, высокомолекулярных - на 19,04% и коллагена на 24,47%. Гипоксия при условии естественного освещения снизила лизис исследуемых белков. Сочетанное действие гипоксии и постоянного освещения повлекло уменьшение лизиса исследуемых белков по сравнению с действием одного только освещения. Совместное действие гипоксии и постоянной темноты имело более выраженное влияние: лизис низкомолекулярных белков уменьшился на 21,89%, высокомолекулярных белков на 30,52% и коллагена на 67,61% по сравнению с действием только одной темноты. Резюме. Експериментально на статевозрілих самців білих щурів за дії постійного освітлення або постійної темряви впродовж 14 діб та переривчастої гіпобаричної гіпоксії (2 год. на добу) встановлено особливості змін протеолітичної активності в тканинах ясен піддослідних тварин. Постійне освітлення не змінило активності протеолізу щодо низько- та високомолекулярних білків, але підвищило інтенсивність лізису колагену на 20,57 %. Протилежний ефект на протеолітичні процеси мала темрява. За умови темряви лізис низькомолекулярних білків зменшився на 25,80%, високомолекулярних - на 19,04 % і колагену на 24,47 %. Гіпоксія за умови природного освітлення знизила лізис досліджуваних білків. Поєднана дія гіпоксії та постійного освітлення спричинила зменшення лізису досліджуваних білків порівняно із дією одного лише освітлення. Спільна дія гіпоксії і постійної темряви мала більш виражений вплив: лізис низькомолекулярних білків зменшився на 21,89 %, високомолекулярних білків на 30,52% і колагену на 67,61 % порівняно із дією лише однієї темряви

Characteristics and treatment regimens across ERS SHARP severe asthma registries

Little is known about the characteristics and treatments of patients with severe asthma across Europe but both are likely to vary. This is the first study in the ERS Severe Heterogeneous Asthma Research collaboration, Patient-centred (SHARP) and it is designed to explore these variations. Therefore, we aimed to compare characteristics of patients in European severe asthma registries and treatments before starting biologicals. This was a cross-sectional retrospective analysis of aggregated data from 11 national severe asthma registries that joined SHARP with established patient databases. Analysis of data from 3233 patients showed many differences in characteristics and life style factors. Current smokers ranged from 0% (Poland, PL, Sweden, SE) to 9.5% (Belgium, BE), mean BMI ranged from 26.2 (Italy) to 30.6 kg·m-2 (UK) and the largest difference in mean pre-bronchodilator FEV1% pred. was 20.9% (Netherlands versus Hungary). Before starting biologicals patients were treated differently between countries: mean ICS dose ranged from 700 to 1335 µg·day-1 between those from Slovenia (SL) versus PL when starting anti-IL-5 antibody and from 772 to 1344 µg·day-1 in those starting anti-IgE (SL versus Spain). Maintenance OCS use ranged from 21.0% (BE) to 63.0% (SE) and from 9.1% (Denmark) to 56.1% (UK) in patients starting anti-IL-5 and anti-IgE, respectively. The severe asthmatic population in Europe is heterogeneous and differs in both clinical characteristics and treatment, often appearing not to comply with the current ERS/ATS guidelines definition of severe asthma. Treatment regimens before starting biologicals were different from inclusion criteria in clinical trials and varied between countries

Low levels of endogenous anabolic androgenic steroids in females with severe asthma taking corticosteroids

Rationale Patients with severe asthma are dependent upon treatment with high doses of inhaled corticosteroids (ICS) and often also oral corticosteroids (OCS). The extent of endogenous androgenic anabolic steroid (EAAS) suppression in asthma has not previously been described in detail. The objective of the present study was to measure urinary concentrations of EAAS in relation to exogenous corticosteroid exposure. Methods Urine collected at baseline in the U-BIOPRED (Unbiased Biomarkers for the Prediction of Respiratory Disease outcomes) study of severe adult asthmatics (SA, n=408) was analysed by quantitative mass spectrometry. Data were compared to that of mild-to-moderate asthmatics (MMA, n=70) and healthy subjects (HC, n=98) from the same study. Measurements and main results The concentrations of urinary endogenous steroid metabolites were substantially lower in SA than in MMA or HC. These differences were more pronounced in SA patients with detectable urinary OCS metabolites. Their dehydroepiandrosterone sulfate (DHEA-S) concentrations were <5% of those in HC, and cortisol concentrations were below the detection limit in 75% of females and 82% of males. The concentrations of EAAS in OCS-positive patients, as well as patients on high-dose ICS only, were more suppressed in females than males (p<0.05). Low levels of DHEA were associated with features of more severe disease and were more prevalent in females (p<0.05). The association between low EAAS and corticosteroid treatment was replicated in 289 of the SA patients at follow-up after 12–18 months. Conclusion The pronounced suppression of endogenous anabolic androgens in females might contribute to sex differences regarding the prevalence of severe asthma

Characteristics and treatment regimens across ERS SHARP severe asthma registries

Little is known about the characteristics and treatments of patients with severe asthma across Europe, but both are likely to vary. This is the first study in the European Respiratory Society Severe Heterogeneous Asthma Research collaboration, Patient-centred (SHARP) Clinical Research Collaboration and it is designed to explore these variations. Therefore, we aimed to compare characteristics of patients in European severe asthma registries and treatments before starting biologicals.This was a cross-sectional retrospective analysis of aggregated data from 11 national severe asthma registries that joined SHARP with established patient databases.Analysis of data from 3236 patients showed many differences in characteristics and lifestyle factors. Current smokers ranged from 0% (Poland and Sweden) to 9.5% (Belgium), mean body mass index ranged from 26.2 (Italy) to 30.6\u2005kg\ub7m-2 (the UK) and the largest difference in mean pre-bronchodilator forced expiratory volume in 1\u2005s % predicted was 20.9% (the Netherlands versus Hungary). Before starting biologicals patients were treated differently between countries: mean inhaled corticosteroid dose ranged from 700 to 1335\u2005\ub5g\ub7day-1 between those from Slovenia versus Poland when starting anti-interleukin (IL)-5 antibody and from 772 to 1344\u2005\ub5g\ub7day-1 in those starting anti-IgE (Slovenia versus Spain). Maintenance oral corticosteroid use ranged from 21.0% (Belgium) to 63.0% (Sweden) and from 9.1% (Denmark) to 56.1% (the UK) in patients starting anti-IL-5 and anti-IgE, respectively.The severe asthmatic population in Europe is heterogeneous and differs in both clinical characteristics and treatment, often appearing not to comply with the current European Respiratory Society/American Thoracic Society guidelines definition of severe asthma. Treatment regimens before starting biologicals were different from inclusion criteria in clinical trials and varied between countries

The effect of the COVID-19 pandemic on severe asthma care in Europe: Will care change for good?

peer reviewedBackground The coronavirus disease 2019 (COVID-19) pandemic has put pressure on healthcare services, forcing the reorganisation of traditional care pathways. We investigated how physicians taking care of severe asthma patients in Europe reorganised care, and how these changes affected patient satisfaction, asthma control and future care. Methods In this European-wide cross-sectional study, patient surveys were sent to patients with a physician-diagnosis of severe asthma, and physician surveys to severe asthma specialists between November 2020 and May 2021. Results 1101 patients and 268 physicians from 16 European countries contributed to the study. Common physician-reported changes in severe asthma care included use of video/phone consultations (46%), reduced availability of physicians (43%) and change to home-administered biologics (38%). Change to phone/video consultations was reported in 45% of patients, of whom 79% were satisfied or very satisfied with this change. Of 709 patients on biologics, 24% experienced changes in biologic care, of whom 92% were changed to home-administered biologics and of these 62% were satisfied or very satisfied with this change. Only 2% reported worsening asthma symptoms associated with changes in biologic care. Many physicians expect continued implementation of video/phone consultations (41%) and home administration of biologics (52%). Conclusions Change to video/phone consultations and home administration of biologics was common in severe asthma care during the COVID-19 pandemic and was associated with high satisfaction levels in most but not all cases. Many physicians expect these changes to continue in future severe asthma care, though satisfaction levels may change after the pandemic. © The authors 2022

Plasma proteins elevated in severe asthma despite oral steroid use and unrelated to Type-2 inflammation

Rationale Asthma phenotyping requires novel biomarker discovery. Objectives To identify plasma biomarkers associated with asthma phenotypes by application of a new proteomic panel to samples from two well-characterised cohorts of severe (SA) and mild-to-moderate (MMA) asthmatics, COPD subjects and healthy controls (HCs). Methods An antibody-based array targeting 177 proteins predominantly involved in pathways relevant to inflammation, lipid metabolism, signal transduction and extracellular matrix was applied to plasma from 525 asthmatics and HCs in the U-BIOPRED cohort, and 142 subjects with asthma and COPD from the validation cohort BIOAIR. Effects of oral corticosteroids (OCS) were determined by a 2-week, placebo-controlled OCS trial in BIOAIR, and confirmed by relation to objective OCS measures in U-BIOPRED. Results In U-BIOPRED, 110 proteins were significantly different, mostly elevated, in SA compared to MMA and HCs. 10 proteins were elevated in SA versus MMA in both U-BIOPRED and BIOAIR (alpha-1-antichymotrypsin, apolipoprotein-E, complement component 9, complement factor I, macrophage inflammatory protein-3, interleukin-6, sphingomyelin phosphodiesterase 3, TNF receptor superfamily member 11a, transforming growth factor-β and glutathione S-transferase). OCS treatment decreased most proteins, yet differences between SA and MMA remained following correction for OCS use. Consensus clustering of U-BIOPRED protein data yielded six clusters associated with asthma control, quality of life, blood neutrophils, high-sensitivity C-reactive protein and body mass index, but not Type-2 inflammatory biomarkers. The mast cell specific enzyme carboxypeptidase A3 was one major contributor to cluster differentiation. Conclusions The plasma proteomic panel revealed previously unexplored yet potentially useful Type-2independent biomarkers and validated several proteins with established involvement in the pathophysiology of SA. © 2022 European Respiratory Society. All rights reserved