105 research outputs found
Mechanisms of Hydroxyurea-Induced Cellular Senescence: An Oxidative Stress Connection?
Hydroxyurea (HU) is a water-soluble antiproliferative agent used for decades in neoplastic and nonneoplastic conditions. HU is considered an essential medicine because of its cytoreduction functions. HU is an antimetabolite that inhibits ribonucleotide reductase, which causes a depletion of the deoxyribonucleotide pool and dramatically reduces cell proliferation. The proliferation arrest, depending on drug concentration and exposure, may promote a cellular senescence phenotype associated with cancer cell therapy resistance and inflammation, influencing neighboring cell functions, immunosuppression, and potential cancer relapse. HU can induce cellular senescence in both healthy and transformed cells in vitro, in part, because of increased reactive oxygen species (ROS). Here, we analyze the main molecular mechanisms involved in cytotoxic/genotoxic HU function, the potential to increase intracellular ROS levels, and the principal features of cellular senescence induction. Understanding the mechanisms involved in HU's ability to induce cellular senescence may help to improve current chemotherapy strategies and control undesirable treatment effects in cancer patients and other diseases
Neutrophil Death in Myeloproliferative Neoplasms: Shedding More Light on Neutrophils as a Pathogenic Link to Chronic Inflammation
Neutrophils are an essential component of the innate immune response, but their prolonged activation can lead to chronic inflammation. Consequently, neutrophil homeostasis is tightly regulated through balance between granulopoiesis and clearance of dying cells. The bone marrow is both a site of neutrophil production and the place they return to and die. Myeloproliferative neoplasms (MPN) are clonal hematopoietic disorders characterized by the mutations in three types of molecular markers, with emphasis on Janus kinase 2 gene mutation (JAK2V617F). The MPN bone marrow stem cell niche is a site of chronic inflammation, with commonly increased cells of myeloid lineage, including neutrophils. The MPN neutrophils are characterized by the upregulation of JAK target genes. Additionally, MPN neutrophils display malignant nature, they are in a state of activation, and with deregulated apoptotic machinery. In other words, neutrophils deserve to be placed in the midst of major events in MPN. Our crucial interest in this review is better understanding of how neutrophils die in MPN mirrored by defects in apoptosis and to what possible extent they can contribute to MPN pathophysiology. We tend to expect that reduced neutrophil apoptosis will establish a pathogenic link to chronic inflammation in MPN
An integrated view on society readiness and initial reaction to COVID-19: A study across European countries
With the wake of the COVID-19 pandemic, the question of society's capability to deal with an acute health crisis is, once again, brought to the forefront. In the core is the need to broaden the perspective on the determinants of a country's ability to cope with the spread of the virus. This paper is about bringing together diverse aspects of readiness and initial reaction to a COVID-19 outbreak. We proposed an integrated evaluation framework which encapsulates six dimensions of readiness and initial reaction. Using a specific multi-level outranking method, we analysed how these dimensions affect the relative positioning of European countries in the early stages of the COVID-19 outbreak. The results revealed that the order of countries based on our six-dimensional assessment framework is significantly reminiscent of the actual positioning of countries in terms of COVID-19 morbidity and mortality in the initial phase of the pandemic. Our findings confirm that only when a country's readiness is complemented by an appropriate societal reaction we can expect a less severe outcome. Moreover, our study revealed different patterns of performance between former communist Eastern European and Western European countries
Stvaranje azot-monoksida izazvano bradikininom nije dovoljno za indukciju gama-globina
Introduction Hydroxycarbamide, used in therapy of hemoglobinopathies, enhances nitric oxide (NO) production both in primary human umbilical vein endothelial cells (HUVECs) and human bone marrow endothelial cell line (TrHBMEC). Moreover, NO increases Ī³-globin and fetal hemoglobin levels in human erythroid progenitors. Objective In order to find out whether simple physiologic stimulation of NO production by components of hematopoietic microenvironment can increase Ī³-globin gene expression, the effects of NO-inducer bradykinin were examined in endothelial cells. Methods The study was performed in co-cultures of human erythroid progenitors, TrHBMEC and HUVECs by ozone-based chemiluminescent determination of NO and real-time quantitative RT-PCR. Results In accordance with previous reports, the endogenous factor bradykinin increased endothelial cell production of NO in a dose- and time-dependent manner (0.1-0.6 Ī¼M up to 30 minutes). This induction of NO in HUVECs and TrHBMEC by bradykinin was blocked by competitive inhibitors of NO synthase (NOS), demonstrating NOS-dependence. It has been shown that bradykinin significantly reduced endothelial NOS (eNOS) mRNA level and eNOS/s-actin ratio in HUVEC (by twofold). In addition, bradykinin failed to increase Ī³-globin mRNA expression in erythroid progenitors only, as well as in co-culture studies of erythroid progenitors with TrHBMEC and HUVEC after 24 hours of treatment. Furthermore, bradykinin did not induce Ī³/Ī² globin ratio in erythroid progenitors in co-cultures with HUVEC. Conclusion Bradykinin mediated eNOS activation leads to short time and low NO production in endothelial cells, insufficient to induce Ī³-globin gene expression. These results emphasized the significance of elevated and extended NO production in augmentation of Ī³-globin gene expression.Uvod Hidroksikarbamid, koji se koristi u leÄenju hemoglobinopatija, podstiÄe stvaranje azot-monoksida (NO) kako u primarnim ljudskim endotelnim Äelijama pupÄane vene (HUVEC), tako i u izmenjenoj endotelnoj Äelijskoj liniji poreklom iz koÅ”tane srži (TrHBMEC). Å taviÅ”e, NO poveÄava stvaranje Ī³-globina i fetalnog hemoglobina u ljudskim progenitorima eritropoeze. Cilj rada Da bismo ustanovili da li jednostavna fizioloÅ”ka stimulacija stvaranja NO od komponenti mikrosredine hematopoeze može poveÄati ekspresiju Ī³-globinskog gena, ispitivali smo efekte bradikinina, veÄ poznatog stimulatora stvaranja NO. Metode rada Studija je izvedena u zajedniÄkim kulturama ljudskih progenitora eritropoeze sa TrHBMEC ili HUVEC i ispitivana hemiluminiscentnim merenjem NO posredstvom ozona, kao i primenom kvantitativnog RT-PCR na genskom nivou. Rezultati U skladu s prethodnim izveÅ”tajima, pokazali smo da endogeni faktor bradikinin poveÄava stvaranje NO u endotelnim Äelijama na dozno i vremenski zavisan naÄin (0,1-0,6 Ī¼M do 30 minuta). Ovo stvaranje NO u HUVEC i TrHBMEC izazvano bradikininom blokirano je od strane konkurentskih inhibitora NO-sintaze (NOS), pokazujuÄi NOS-zavisnost. Utvrdili smo da bradikinin znaÄajno smanjuje stvaranje iRNK endotelne forme NOS (eNOS), kao i odnos eNOS i Ī²-aktina u HUVEC (dvostruko manje). Pored toga, bradikinin ne poveÄava ekspresiju iRNK Ī³-globinskog gena ni u zasebnim progenitorima eritropoeze, niti u zajedniÄkim kulturama progenitora eritropoeze sa TrHBMEC ili HUVEC posle 24 sata tretmana. Bradikinin ne menja ni odnos Ī³ i Ī² globina u zajedniÄkim kulturama progenitora eritropoeze sa HUVEC. ZakljuÄak Aktivacija eNO_ izazvana bradikininom dovodi do kratkog i malog poveÄanja NO u endotelnim Äelijama, Å”to je nedovoljno da podstakne ekspresiju gena za Ī³-globin. Ovi rezultati naglaÅ”avaju važnost poveÄanog i produženog stvaranja NO radi stimulacije ekspresije Ī³-globina
Gender Difference in SARS-CoV-2 Stimulation of Hyperinflammatory Response in Patients with COVID-19
Background: Although women and men have the same prevalence, men with
COVID-19 are more at risk for worse outcomes and death, independent of age.
Methods: To observe the hyperinflammatory response regarding sex, we will measure
the levels of inflammatory cytokines: interleukin-6 (IL-6), IL-1Ī², tumor necrosis
factor-alpha (TNF-Ī±), monocyte chemoattractant protein-1 (MCP-1), IL-10, interferon-
gamma (IFN-Ī³), IL-8, transforming growth factor-beta 1 (TGF-Ī²1), analyzed by
ELISA, in plasma of 130 COVID-19 patients at diagnosis and correlate them with clinical
parameters. Besides, we checked the quality of life of patients up to 3 months
after hospitalization.
Results: Pro-inflammatory IL-6 was significantly (p<0.01) increased in male COVID-19
patients compared to healthy male volunteers (4.7-fold) and female COVID-19 patients
(1.75-fold). IL-6 was positively correlated to INR, aPTT (p<0.001), and ferritin (p<0.05),
while INR with CRP (p<0.05). IL-8 was significantly increased in female COVID-19 patients
compared to healthy female volunteers (p<0.01, 2.5-fold) and male COVID-19 patients
(p<0.05). TNF-Ī± was significantly (p<0.05) increased in male COVID-19 patients
compared to healthy male volunteers. MCP-1 and IFN-Ī³ were significantly increased
in female COVID-19 patients compared to healthy female volunteers (p<0.01). Anti-inflammatory
TGF-Ī²1 was decreased in COVID-19 patients regardless of gender. Most
patients were men (75%) with chronic disorders (59%, mostly hypertension). COVID-19
reduced their social (32%) and physical activities (34%) after 6 weeks of diagnosis, but
further on reduced in additional 3 months (social 55%) with depression (22%).
Conclusions: Inflammatory response is generally increased in COVID-19 patients
with specific cytokines in accordance with gender
Quantitative Proteome Heterogeneity in Myeloproliferative Neoplasm Subtypes and Association with JAK2 Mutation Status
Apart from well-known genetic abnormalities, several studies have reported variations in protein expression in Philadelphianegative myeloproliferative neoplasm (MPN) patients that could contribute toward their clinical phenotype. In this context, a quantitative mass spectrometry proteomics protocol was used to identify differences in the granulocyte proteome with the goal to characterize the pathogenic role of aberrant protein expression in MPNs. LC/MS-MS (LTQ Orbitrap) coupled to iTRAQ labeling showed significant and quantitative differences in protein content among various MPN subtypes [polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF)], and according to the genetic status of JAK2 (JAK2V617F presence and JAK2V617F allele burden). A number of differentially expressed proteins were identified, with the most frequent being members of the RAS GTPase family and oxidative stress regulatory proteins. Subsequent analysis found that calreticulin (CALR), known to be involved in calcium homeostasis and apoptotic signaling, was overexpressed in JAK2V617F granulocytes compared with JAK2 wild type and independently of the JAK2V617F allele burden. Finally, it was demonstrated, in a Ba/F3 cell model, that increased calreticulin expression was directly linked to JAK2V617F and could be regulated by JAK2 kinase inhibitors. Implications: In conclusion, these results reveal proteome alterations in MPN granulocytes depending on the phenotype and genotype of patients, highlighting new oncogenic mechanisms associated with JAK2 mutations and overexpression of calreticulin
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