Znaczenie zjawiska alloreaktywności indukowanej infekcjami wirusowymi u chorych po przeszczepieniach allogenicznych krwiotwórczych komórek macierzystych

Viral infection activated alloreactive peripheral memory T-cells present in the host are considered as one of the causes of transplant related complications during post-transplant period of unrelated donor and haploidentical graft transplantation procedures. Antibody and T-cell receptor coding genes homology and their analogous rearrangement process help to understand cellular and humoral alloreactivity, mediated by alloreactive memory T-cells and antibodies, respectively. Simple tests using single antigen presenting cells or human leukocyte antigen (HLA)-mismatched recipient peripheral blood mononuclear cells vs. virus specific donor T-cells and more sophisticated natural killer cells degranulation marker assays based on flow cytometry enable to rule out or confirm alloreactivity thus increasing the chance of appropriate post-transplant treatment path selection.Krzyżowa odpowiedź alloreaktywnych limfocytów T pamięci aktywowanych infekcjami wirusowymi jest jedną z przyczyn powikłań u pacjentów poddawanych procedurze przeszczepienia krwiotwórczych komórek macierzystych od dawcy niespokrewnionego oraz przeszczepienia haploidentycznego. Homologia mechanizmów rearanżacji genów V(D)J kodujących receptory komórek T oraz część zmienną przeciwciał ułatwia zrozumienie zjawiska alloreaktywności komórkowej i humoralnej, w której pośredniczą odpowiednio limfocyty T pamięci wykazujące reaktywność krzyżową w stosunku do alloantygenów oraz alloreaktywne przeciwciała przeciw układowi ludzkich antygenów leukocytarnych. Proste testy oparte na pomiarze aktywacji komórek pamięci dawcy w kontakcie z komórkami prezentującymi niezgodny antygen oraz bardziej skomplikowane procedury oparte na cytometrycznym oznaczaniu markera degranulacji komórek naturalnej cytotoksyczności pozwalają pozyskać informacje o stopniu możliwych powikłań w przypadku alloreaktywnej odpowiedzi komórek biorcy na przeszczep

Oxidative Stress and Microcirculatory Flow Abnormalities in the Ventricles during Atrial Fibrillation

Patients with atrial fibrillation (AF) often present with typical angina pectoris and mildly elevated levels of cardiac troponin (non-ST-segment elevation myocardial infarction) during an acute episode of AF. However, in a large proportion of these patients, significant coronary artery disease is excluded by coronary angiography, which suggests that AF itself influences myocardial blood flow. The present review summarizes the effect of AF on the occurrence of ventricular oxidative stress, redox-sensitive signaling pathways and gene expression, and microcirculatory flow abnormalities in the left ventricle

Clock and clock-controlled genes are differently expressed in the retina, lamina and in selected cells of the visual system of Drosophila melanogaster

The retina and the first optic neuropil (lamina) of Drosophila show circadian rhythms in various processes. To learn about the regulation of circadian rhythms in the retina and lamina and in two cell types, glial and the lamina L2 interneurons, we examined expression of the following clock genes; per, tim, clk, and cry and clock-controlled genes (ccgs); Atpα, nrv2, brp, Pdfr. We found that the expression of gene studied is specific for the retina and lamina. The rhythms of per and tim expression in the retina and glial cells are similar to that observed in the whole head and in clock neurons, while they differ in the lamina and L2 cells. In both the retina and lamina, CRY seems to be a repressor of clk expression. In L2 interneurons per expression is not cyclic indicating the other function of PER in those cells than in the circadian molecular clock. In contrast to per and tim, the pattern of clk and cry expression is similar in both the retina and lamina. The retina holds the autonomous oscillators but the expression of cry and ccgs, Atpα and nrv2, is also regulated by inputs from the pacemaker transmitted by PDF and ITP neuropeptides

Number of circulating pro-angiogenic cells, growth factor and anti-oxidative gene profiles might be altered in type 2 diabetes with and without diabetic foot syndrome

Aims/Introduction. Type 2 diabetes is often complicated by diabetic foot syndrome (DFS). We analyzed the circulating stem cells, growth factor and anti-oxidant gene expression profiles in type 2 diabetes patients without or with different forms of DFS. Materials and Methods. Healthy volunteers (n = 13) and type 2 diabetes patients: (i) without DFS (n = 10); or with (ii) Charcot osteoneuropathy (n = 10); (iii) non-infected (n = 17); (iv) infected (n = 11); and (v) healed ulceration were examined (n = 12). Peripheral blood endothelial progenitor cells (EPC), mesenchymal stem cells (MSC), hematopoietic stem cells (HSC) and very small embryonic-like (VSEL) cells were phenotyped using flow cytometry. Plasma cytokine concentrations and gene expressions in blood cells were measured by Luminex and quantitative real-time polymerase chain reaction assays, respectively. Results. Patients with non-complicated type 2 diabetes showed reduced HMOX1 expression, accompanied by HMOX2 upregulation, and had less circulating EPC, MSC or HSC than healthy subjects. In contrast, VSEL cells were elevated in the type 2 diabetes group. However, subjects with DFS, even with healed ulceration, had fewer VSEL cells, more CD45-CD29+CD90+MSC, and upregulated HMOX1 when compared with the type 2 diabetes group. Patients with Charcot osteopathy had lowered plasma fibroblast growth factor-2. Elevated plasma tumor necrosis factor-α and decreased catalase expression was found in all diabetic patients. Conclusions. Patients with type 2 diabetes and different forms of DFS have an altered number of circulating stem cells. Type 2 diabetes might also be associated with a changed plasma growth factor and anti-oxidant gene expression profile. Altogether, these factors could contribute to the pathogenesis of different forms of DFS

Cobalt protoporphyrin IX increases endogenous G-CSF and mobilizes HSC and granulocytes to the blood

Granulocyte colony-stimulating factor (G-CSF) is used in clinical practice to mobilize cells from the bone marrow to the blood; however, it is not always effective. We show that cobalt protoporphyrin IX (CoPP) increases plasma concentrations of G-CSF, IL-6, and MCP-1 in mice, triggering the mobilization of granulocytes and hematopoietic stem and progenitor cells (HSPC). Compared with recombinant G-CSF, CoPP mobilizes higher number of HSPC and mature granulocytes. In contrast to G-CSF, CoPP does not increase the number of circulating T cells. Transplantation of CoPP-mobilized peripheral blood mononuclear cells (PBMC) results in higher chimerism and faster hematopoietic reconstitution than transplantation of PBMC mobilized by G-CSF. Although CoPP is used to activate Nrf2/HO-1 axis, the observed effects are Nrf2/HO- 1 independent. Concluding, CoPP increases expression of mobilization- related cytokines and has superior mobilizing efficiency compared with recombinant G-CSF. This observation could lead to the development of new strategies for the treatment of neutropenia and HSPC transplantation

Curcumin enhances the cytogenotoxic effect of etoposide in leukemia cells through induction of reactive oxygen species

Curcumin may exert a more selective cytotoxic effect in tumor cells with elevated levels of free radicals. Here, we investigated whether curcumin can modulate etoposide action in myeloid leukemia cells and in normal cells of hematopoietic origin. HL-60 cell line, normal myeloid progenitor cluster of differentiation (CD)-34+ cells, and granulocytes were incubated for 4 or 24 hours at different concentrations of curcumin and/or etoposide. Brown Norway rats with acute myeloid leukemia (BNML) were used to prove the influence of curcumin on etoposide action in vivo. Rats were treated with curcumin for 23 days and etoposide was administered for the final 3 days of the experiment. Curcumin synergistically potentiated the cytotoxic effect of etoposide, and it intensified apoptosis and phosphorylation of the histone H2AX induced by this cytostatic drug in leukemic HL-60 cells. In contrast, curcumin did not significantly modify etoposide-induced cytotoxicity and H2AX phosphorylation in normal CD34+ cells and granulocytes. Curcumin modified the cytotoxic action of etoposide in HL-60 cells through intensification of free radical production because preincubation with N-acetyl-l-cysteine (NAC) significantly reduced the cytotoxic effect of curcumin itself and a combination of two compounds. In contrast, NAC did not decrease the cytotoxic effect of etoposide. Thus, oxidative stress plays a greater role in the cytotoxic effect of curcumin than that of etoposide in HL-60 cells. In vitro results were confirmed in a BNML model. Pretreatment with curcumin enhanced the antileukemic activity of etoposide in BNML rats (1.57-fold tumor reduction versus etoposide alone; P<0.05) and induced apoptosis of BNML cells more efficiently than etoposide alone (1.54-fold change versus etoposide alone; P<0.05), but this treatment protected nonleukemic B-cells from apoptosis. Thus, curcumin can increase the antileukemic effect of etoposide through reactive oxygen species in sensitive myeloid leukemia cells, and it is harmless to normal human cells

Role of HMOX1 promoter genetic variants in chemoresistance and chemotherapy induced neutropenia in children with acute lymphoblastic leukemia

Whilst the survival rates of childhood acute lymphoblastic leukemia (ALL) have increased remarkably over the last decades, the therapy resistance and toxicity are still the major causes of treatment failure. It was shown that overexpression of heme oxygenase-1 (HO-1) promotes proliferation and chemoresistance of cancer cells. In humans, the HO-1 gene (HMOX1) expression is modulated by two polymorphisms in the promoter region: (GT)n-length polymorphism and single-nucleotide polymorphism (SNP) A(−413)T, with short GT repeat sequences and 413-A variants linked to an increased HO-1 inducibility. We found that the short alleles are significantly more frequent in ALL patients in comparison to the control group, and that their presence may be associated with a higher risk of treatment failure, reflecting the role of HO-1 in chemoresistance. We also observed that the presence of short alleles may predispose to develop chemotherapy-induced neutropenia. In case of SNP, the 413-T variant co-segregated with short or long alleles, while 413-A almost selectively co-segregated with long alleles, hence it is not possible to determine if SNPs are actually of phenotypic significance. Our results suggest that HO-1 can be a potential target to overcome the treatment failure in ALL patients