Granulocyte Apoptosis Research Articles

Role of mTORC1 Signaling in Regulating the Immune Function of Granulocytes in Teleost Fish.

Granulocytes are crucial innate immune cells that have been extensively studied in teleost fish. Studies in mammals have revealed that mechanistic target of rapamycin complex 1 (mTORC1) signaling acts as a significant immune regulatory hub, influencing granulocyte immune function. To investigate whether mTORC1 signaling also regulates the immune function of granulocytes in teleost fish, we established a model of RAPA inhibition of the mTORC1 signaling pathway using granulocytes from largemouth bass (Micropterus salmoides). Our results demonstrated that inhibition of mTORC1 signaling promoted autophagy and apoptosis of granulocytes while inhibiting cell proliferation. Moreover, inhibition of the mTORC1 signaling pathway enhanced the phagocytosis capacity of granulocytes. Collectively, our findings revealed the evolutionarily conserved role of the mTORC1 signaling pathway in regulating granulocyte responses, thus providing novel insights into the function of granulocytes in teleost fish.

The Impact of TRAIL on the Immunological Milieu during the Early Stage of Abdominal Sepsis

Despite intensive scientific efforts, the therapy of peritonitis is presently limited to symptomatic measures, including infectious source control and broad-spectrum antibiotics. Promising therapeutic approaches to reduce morbidity and mortality are still missing. Within the early phase of abdominal sepsis, apoptosis of neutrophil granulocytes is inhibited, which is linked to tissue damage and septic shock. TNF-related apoptosis-inducing ligand (TRAIL) is a promising agent to stimulate neutrophil apoptosis. However, the underlying mechanisms have not been elucidated so far. The objective of the present study was to characterize the molecular mechanisms of TRAIL-stimulated apoptosis in early abdominal sepsis. Therefore, the murine sepsis model Colon ascendens stent peritonitis (CASP) was applied in wild type (WT) and TRAIL knock-out (TRAIL-/-) C57/BL6j mice. Neutrophil granulocytes were isolated from spleen, blood, bone marrow, and peritoneal lavage using magnetic-activated cell sorting. Neutrophil maturation was analyzed by light microscopy, and apoptotic neutrophils were quantified by fluorescence-activated cell sorting (FACS). Western blot and FACS were used to investigate expression changes in apoptotic proteins and TRAIL receptors. The impact of TRAIL-induced apoptosis was studied in vitro. In septic mice (CASP 6 h), the number of neutrophils in the BM was reduced but increased in the blood and peritoneal lavage. This was paralleled by an increased maturation of neutrophils from rod-shaped to segmented neutrophils (right shift). In vitro, extrinsic TRAIL stimulation did not alter the apoptosis level of naïve neutrophils but stimulated apoptosis in neutrophils derived from septic WT and TRAIL-/- mice. Neutrophils of the bone marrow and spleen showed enhanced protein expression of anti-apoptotic Flip, c-IAP1, and McL-1 and reduced expression levels of pro-apoptotic Bax in neutrophils, which might correlate with apoptosis inhibition in these cells. CASP increased the expression of intrinsic TRAIL in neutrophils derived from the bone marrow and spleen. This might be explained by an increased expression of the TRAIL receptors DR5, DcR1, and DcR2 on neutrophils in sepsis. No differences were observed between septic or naïve WT and TRAIL-/- mice. In conclusion, the present study shows that neutrophil granulocytes are sensitive to TRAIL-stimulated apoptosis in the early stage of abdominal sepsis, emphasizing the promising role of TRAIL as a therapeutic agent.

Pharmacological Induction of Granulocyte Cell Death as Therapeutic Strategy.

Apoptosis is central for the maintenance of health. In the immune system, apoptosis guarantees proper development of immune cells and shutdown of immune reactions by the coordinated elimination of activated immune cells. Limitation of the life span of granulocytes is important, as overactivation of these cells is associated with chronic inflammation and collateral tissue damage. Consequently, targeted induction of granulocyte apoptosis may be beneficial in the course of respective immune disorders. Anti-inflammatory drugs such as glucocorticoids and monoclonal antibodies against IL-5Rα exert their function in part by triggering eosinophil apoptosis. Agonistic antibodies targeting Siglec-8 or death receptors are tested (pre)clinically. Moreover, a new class of inhibitors targeting antiapoptotic BCL-2 proteins shows great promise for anticancer treatments. Because of their specificity and tolerable side effects, these so-called BH3 mimetics may be worthwhile to evaluate in inflammatory disorders. Here, we review past and recent data on pharmacological apoptosis induction of granulocytes and highlight respective therapeutic potential.

Acupuncture affects the apoptosis of eosinophilic granulocytes in lung tissue of asthmatic rats by regulating the P38MAPK signaling pathway

To investigate the effects of acupuncture on phosphorylated P38 mitogen-activated protein kinase (p-P38MAPK), intercellular adhesion molecule-1 (ICAM-1), interferon γ (IFN-γ), and eosinophilic granulocytes (EOS) in lung tissue of asthmatic rats, and to explore the mechanism of acupuncture in regulating the apoptosis of EOS. Clean-grade male Wistar rats were randomly divided into normal, model, dexamethasone and acupuncture groups, 8 rats in each group. The asthmatic model was established by intraperitoneal injection of mixture suspension (1 mL) of 10% ovalbumin and 10% Al(OH)_3+ normal saline, followed by inhalation of atomized 1% ovalbumin solution for 30 min, once daily for 2 weeks to trigger occurrence of asthmatic symptoms. The rats in dexamethasone group were intraperitoneally injected with 0.9 mg/kg dexamethasone since day 15 once a day for two consecutive weeks. In the acupuncture group, bilateral "Feishu" (BL13), "Pishu" (BL20), "Shenshu" (BL23), "Dingchuan" (EX-B1), and "Danzhong" (CV17) were selected for acupuncture treatment once every other day since day 15 for two consecutive weeks. Uniform reinforcing and reducing manipulation was carried out, and the needles were retained for 30 min. The pathological changes of the lung tissue were observed by hematoxylin-eosin (HE) staining. The apoptosis of EOS in the lung tissue of rats was detected by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. The expression of p-P38MAPK in the lung tissue was detected by Western blot. The protein and mRNA levels of ICAM-1 and IFN-γ in the lung tissue were determined by immunohistochemistry and real-time PCR, respectively. The results of HE staining showed that the pulmonary alveoli and surrounding tissues were intact with no inflammatory cell infiltration in the normal group. The model group showed massive exudation of inflammatory materials and thickened pulmonary interstitium. The dexamethasone group and acupuncture group showed less damage of the alveolar structure and only a small number of inflammatory cells around the airway. Compared with the normal group, the apoptosis rate of EOS in lung tissue was decreased (P<0.01), the expression levels of p-P38MAPK and ICAM-1 proteins and mRNAs in the lung tissue were up-regulated (P<0.01), while the expression levels of IFN-γ protein and mRNA in the lung tissue were down-regulated (P<0.01) in the model group. Compared with the model group, the apoptosis rate of EOS in the lung tissue was increased (P<0.05), the expression levels of p-P38MAPK and ICAM-1 proteins and mRNAs in the lung tissue were down-regulated (P<0.01, P<0.05), while the expression levels of IFN-γ protein and mRNA were up-regulated (P<0.05, P<0.01) in the dexamethasone and acupuncture groups. Acupuncture may inhibit the P38MAPK signaling pathway, down-regulate ICAM-1 expression, and up-regulate IFN-γ expression to promote the apoptosis of EOS and reduce EOS aggregation, thus alleviating the inflammatory response of airway in asthma.

ЗВ’ЯЗОК АПОПТОЗУ ТА ВТОРИННОГО НЕКРОЗУ ЛЕЙКОЦИТІВ ІЗ АКТИВНІСТЮ ХВОРОБИ ТА КЛІНІЧНОЮ МАНІФЕСТАЦІЄЮ У ПАЦІЄНТІВ З НА СЧВ

The presence of several different autoantibodies (auto-AT) at the same time is a specific peculiarity of the “autoantibody profile” of SLE (systemic lupus erythematosus). It is known that the induction of auto-AT formation involves both nonspecific and antigen-specific immunoregulatory disorders. In apoptosis, the primary changes in the cell membrane composition or/and the excretion of intracellular compounds into the intercellular milieu lead to an inflammatory reaction.&nbsp; The purpose of the study was to highlight the connection between apoptosis and secondary necrosis of granulocytes and mononuclear (lymphocytes and monocytes) with inflammation activity in patients with SLE to improve diagnosis and basic therapy efficacy. In patients with SLE, secondary necrosis of granulocytes was 3.4 times higher compared to healthy control. Moreover, the level of apoptotic monocytes was 1.87 times higher, and secondary necrosis of monocytes was 5.58 times higher than healthy control. The secondary necrosis of lymphocytes was higher 9.0 times than in the case of healthy control. The usage of Apolect technology in patients with SLE allows differentiating various cell types of immunological inflammation with the analysis of the degree of apoptosis and secondary necrosis of immunocompetent cells (granulocytes, monocytes, lymphocytes) to determine the aggressiveness of cytostatic therapy and predict the development of complications of this disease.

Bone marrow granulocytes downregulate IL-1β and TNF production and the microbicidal activity of inflammatory macrophages.

Macrophages play critical roles in inflammation and defense against pathogens, as well as in the return to tissue homeostasis. Macrophage subpopulations displaying antagonistic phenotypes are generally classified as proinflammatory M1, implicated in antipathogen and antitumoral activities, or as anti-inflammatory M2, associated with tissue repair. Granulocytic and monocytic myeloid-derived suppressor cells recruited from the bone marrow to tissues and phagocytosis of apoptotic neutrophils can attenuate macrophage microbicidal activity. Here, we showed that bone marrow neutrophils, but not thioglycollate-recruited neutrophils, directly suppress the responses of macrophages that were previously committed to an inflammatory phenotype. Cocultures of inflammatory macrophages with bone marrow CD11b+Ly6Ghi granulocytes led to reduced release of IL-1β, TNF-α, and IL-6 by macrophages after lipopolysaccharide stimulation. The suppressive activity was unrelated to granulocyte apoptosis or to secreted factors and required cell-to-cell contact. The suppressive effect was paralleled by reduction in the nuclear levels of the NF-κB p65 subunit, but not of the p50 subunit. Furthermore, bone marrow granulocytes decreased the phagocytic activity of macrophages and their capacity to kill intracellular Escherichia coli. Taken together, these results show that bone marrow granulocytes can function as suppressors of the proinflammatory activity and microbial-killing responses of macrophages.

PMN Apoptosis Induced by SNHG11 through the Inhibition of Endotoxin-induced Acute Lung Injury NF-κB Pathway.

To investigate the impacts of small nucleolar RNA host gene 11 (SNHG11) on nuclear factor kappa-B (NF-κB) pathway and polymorphonuclear granulocyte (PMN) apoptosis in rats with endotoxin-induced acute lung injury (ALI). Forty rats were the experimental subjects. They were randomly grouped as a control group (Group C), an endotoxin group (Group E), an inhibitor group (Group I), and an activator group (Group A), with 10 rats in each group. The endotoxin-educed ALI rat model was built. Arterial Blood Gas Test (ABGT) was performed, and the Wet/Dry (W/D) ratio of lung weight was determined. The pathological variations in rat pulmonary tissues were scrutinized and scored. PMN in peripheral blood was isolated; its apoptosis was assessed, and its total NF-κB p65 and p-NF-κB p65 expressions were assessed. The expression of SNHG11 mRNA in pulmonary tissues was assessed. Results: Compared to Group C, the W/D ratios and pathological scores of Group E, Group I, and Group A boosted notably (P <0.05), while their ABGT indicators and PMN apoptosis rates dropped (P <0.05). Compared to Group E and Group I, the W/D ratio and pathological score of Group A dropped notably (P <0.05), while its ABGT indicators and PMN apoptosis rate boosted (P <0.05). Compared to Group C, the p-NF-κB p65 and SNHG11 expressions were boosted in Group E, Group I, and Group A (P <0.05); compared to Group E and Group I, the p-NF-κB p65 and SNHG11 expressions in Group A dropped (P <0.05). SNHG11 could relieve endotoxin-induced ALI, which might be associated with the acceleration of PMN apoptosis and the inhibition of the NF-κB pathway.

Perkinsus marinus suppresses in vitro eastern oyster apoptosis via IAP-dependent and caspase-independent pathways involving TNFR, NF-kB, and oxidative pathway crosstalk

The protozoan parasite Perkinsus marinus causes Dermo disease in eastern oysters, Crassostrea virginica, and can suppress apoptosis of infected hemocytes using incompletely understood mechanisms. This study challenged hemocytes in vitro with P. marinus for 1 h in the presence or absence of caspase inhibitor Z-VAD-FMK or Inhibitor of Apoptosis protein (IAP) inhibitor GDC-0152. Hemocytes exposure to P. marinus significantly reduced granulocyte apoptosis, and pre-incubation with Z-VAD-FMK did not affect P. marinus-induced apoptosis suppression. Hemocyte pre-incubation with GDC-0152 prior to P. marinus challenge further reduced apoptosis of granulocytes with engulfed parasite, but not mitochondrial permeabilization. This suggests P. marinus-induced apoptosis suppression may be caspase-independent, affect an IAP-involved pathway, and occur downstream of mitochondrial permeabilization. P. marinus challenge stimulated hemocyte differential expression of oxidation-reduction, TNFR, and NF-kB pathways. WGCNA analysis of P. marinus expression in response to hemocyte exposure revealed correlated protease, kinase, and hydrolase expression that could contribute to P. marinus-induced apoptosis suppression.

Evaluating the Apoptotic Cell Death Modulatory Activity of Nanoparticles in Men and Women Neutrophils and Eosinophils

Apoptosis is an important cell death mechanism for the resolution of inflammation. Neutrophil spontaneous apoptosis rates were reported to be slightly different in men and women and to be modulated by female sex hormones. The aim of this study was to determine whether different nanoparticles (NPs) will alter the neutrophil and eosinophil apoptotic rates differently in men and women. Using the antiapoptotic cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF) and the proapoptotic plant lectin Viscum album agglutinin-I (VAA-I) as controls, we found that these factors respectively delay and induce apoptosis in both neutrophils and eosinophils with apoptotic rates remarkably similar in both sexes. The polyamidoamine (PAMAM) dendrimers of generation 0 (G0) and G3 slightly, but not significantly, accelerate neutrophil apoptosis regardless of sex. Zinc oxide (ZnO), titanium dioxide (TiO2), cerium dioxide (CeO2), and palladium (Pd) but not platinum (Pt) NPs were found to significantly delay neutrophil apoptosis. When results were compared between men and women, only ZnO and Pd NPs were found to significantly delay neutrophil apoptosis in men while ZnO, TiO2, CeO2, and Pt NPs inhibit apoptosis in women neutrophils. In eosinophils, G3, but not G0 NPs, significantly accelerate apoptosis in women. ZnO, Pt, and Pd NPs significantly delay eosinophil apoptosis but only in women. Unlike neutrophils, TiO2 and CeO2 NPs did not significantly delay eosinophil apoptosis. We propose that future studies aiming at determining potential effect NPs on cellular biological processes should incorporate a sex-based analysis based on the differences reported here studying the impact of NPs on human granulocyte apoptosis.

Susceptibility to Spontaneous Apoptosis of Peripheral Blood Granulocytes from Patients with Myelodysplastic Syndrome and Chronic Myelomonocytic Leukemia.

Introduction: Myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemias (CMML) constitute a heterogeneous group of clonal hematopoietic diseases. Cytopenias are induced by an apoptosis-mediated bone marrow suppression mechanism. Survival blood cells may exhibit resistance to bone marrow apoptosis and may constitute useful markers of the disease.Patients and Methods: Peripheral blood granulocytes were isolated from 14 healthy volunteers, 10 patients with MDS (AR 5, ARSA 1, AREB 4) and 4 patients with CMML using a standard method with dextran sulfate and ficoll-hypaque. Apoptosis was quantified by the percentage of anexina V (ANV) and propidium iodide (PI) cells, changes in mitochondrial membrane potential (JC-1) using flow cytometry and expression of bcl-2, bax, bcl-x, XIAP and mcl-1 by Western blot analysis at 0h. Granulocyte apoptosis was evaluated at 0h and after incubation at 37°C for 24h in RPMI medium enriched with serum from each individual. Statistical significance was determined using the two-tailed Student's t-test considering p<0.05 significant values.Results: Elevated percentages of early (ANV+ IP-) and late (ANV+ IP+) apoptotic granulocytes were found after incubation for 24h in patients and volunteers. Differences in the ratio of early and late apoptotic granulocytes between patients and volunteers were not statistically significant. Similar results were obtained when changes in mitochondrial membrane potential were analyzed. Circulating granulocytes from healthy volunteers and from patients contained high levels of proapoptotic Bax protein. No patient expressed antiapoptotic bcl-2, bcl-x, XIAP and mcl-1 proteins.Conclusion: Granulocytes from patients with MDS and CMML do not exhibit lower susceptibility to spontaneous apoptosis as compared to healthy individuals.

Gadolinium Orthovanadate GdVO4:Eu3+ Nanoparticles Ameliorate Carrageenan-Induced Intestinal Inflammation

Gadolinium orthovanadate GdVO4:Eu3+ nanoparticles (VNPs) have been shown to scavenge reactive oxygen species (ROS), making them a promising therapeutic agent in inflammation. This study aims to assess the effects of VNPs administered orally on E407a-induced inflammation. Materials and Methods: Fragments of the small intestine of 8 rats treated orally with a carrageenan-containing food additive E407a at a dose of 140 mg / kg of weight during 2 weeks, 8 animals orally exposed to both E407a and VNPs at a dose of 20 μg / kg of weight during the same period of time, and 8 control rats were stained routinely and immunostained for CD3 and CD68 with the subsequent immunohistochemical scoring. Moreover, analysis of viability and cell death modes of granulocytes was performed by flow cytometry using Annexin V and 7-aminoactinomycin D (7-AAD). Results: Oral exposure to the food additive E407a resulted in the development of enteritis associated with altered small intestinal morphology, infiltration of the lamina propria with macrophages and T-lymphocytes, and activation of peripheral blood granulocyte apoptosis. VNPs administered against the background of E407a-induced slight intestinal inflammation improved small intestinal morphology, decreased infiltration rate of the immune cells mentioned above without affecting the intensity of granulocyte apoptosis. Conclusion: Oral administration of VNPs ameliorates E407a-induced enteritis.

Anti-proliferative, antioxidant effects of methanol extract of Calotropis procera leaf on lung cancer cells (H1299) and its ameliorative effect on expression of CD146 on blood cells

BackgroundCalotropis procera leaf is one of the plants commonly utilized in phytomedicine in Nigeria. The present investigation explored the use of the extracts on cell viability and apoptosis respectively. In this study, the expression of the Cluster of differentiation 146 (CD146) in the blood of lung cancer patients on regulatory T cells (Tregs) was determined. The antioxidant and anti-proliferative effects of methanol extracts of Caloropis procera leaf on lung cancer cell H1299 were investigated.MethodsFrom the flow cytometry, the expression of the CD146+ in the T cells were evaluated using the healthy patient, adenocarcinoma, squamous, and small cell lung cancer respectively. The apoptosis of granulocytes, monocytes, lymphocytes, CD4+, and Treg were determined by 7-amino-actinomycin D/Annexin V-Allophycocyanin (APC) staining during the resting stage and after 24 h respectively. Immunofluorescence was conducted. Cell viability assay, hydroxyl (OH), hydrogen peroxide (H2O2) and nitric oxide (NO) scavenging radicals were conducted. Reducing power and flavonoid content of Calotropis procera were investigated. The effect of the Calotropis procera at different concentrations at 24hrs was determined.ResultsFrom the flow cytometry, the expression of the CD146+ on the T cells includes 4.60 % in healthy patients, 10.10, 12.20, 9.80 % in adenocarcinoma, squamous and small cell lung cancer. The apoptosis of granulocytes, monocytes, lymphocytes, CD4+ and Treg were determined by 7-amino-actinomycin D/Annexin V-APC staining during the resting stage and after 24 h which indicate that apoptosis also occurred on Treg. Immunofluorescence shows the presence of CD146 in lung cancer patient’s tissues. The methanol extracts of Calotropis procera leaf have antioxidant and anti-proliferative effects. Methanol extract of Calotropis procera leaf reduced CD146 expression on blood cells at 24 h.ConclusionIncreased CD146 expression in the Treg of lung cancer patients indicates that it may be a possible target for the treatment of lung cancer by utilizing potent immunotherapy or natural products such as methanol extract of Calotropis procera leaf which may ameliorate the expression of CD146. Calotropis procera has antioxidant, inhibitory capacity on H1299 lung cancer cells, and the ability to scavenge OH, H2O2, and NO radicals. Hence, this investigation strengthens the phyto-medicinal properties of Calotropis procera.

Synthetic Oligodeoxynucleotides in the Regulation of Neutrophil Apoptosis

Synthetic oligodeoxynucleotides (ODNs) mimic the immunostimulatory activity of viral/microbial/host DNA. The present study was undertaken to investigate the effects of ODNs on polymorphonuclear leukocyte (PMNL, neutrophil) apoptosis. Neutrophils are essential for innate immunity, and the ability of ODNs to influence neutrophil functions makes them promising for use in immunotherapy. Little is known about the effects of different ODN structures on neutrophil life and death. We studied how ODNs affect both unconstrained and bacterially suppressed apoptosis of neutrophilic granulocytes. Apoptosis modulation by phosphodiester ODNs and by structures with different numbers of phosphorothioate substitutions was compared. In the case of CpG-ODNs, it was the compounds with phosphorothioate bonds that had a pronounced proapoptotic effect upon short-term (4-6 hours) exposure. After 24 hours, the most effective were A-class CpG-ODNs, with phosphodiester inner core and phosphorothioate oligoguanosines (poly(g)) attached to the ends, as well as telomeric phosphodiester (TTAGGG)n repeats flanking with 3’- and 5’- poly(g) sequences, like those in A-class CpG-ODNs. Intracellular oxidant accumulation often triggers apoptotic pathways in neutrophils. Phosphorothioate-containing CpG-ODNs concomitantly stimulated production of nitric oxide and superoxide, which may rapidly combine to generate peroxynitrite. ODNs with phosphodiester bonds did not activate oxidant production. We experimentally showed the anti-apoptotic activity of bacteria Salmonella typhimurium. CpG-ODNs prevented bacteria-associated inhibition of apoptosis at doses that do not affect the lifespan of resting cells. The pro-oxidant effect of low concentrations of CpG ODNs was not sufficient to trigger irreversible pro-apoptotic mechanisms, but the sensitivity of PMNLs to ODNs as modulators of apoptosis, increased significantly under conditions of infectious inflammation. Telomeric phosphodiester (TTAGGG)4 repeats with phosphorothioate oligoguanosines attached to the ends were less effective in prevention of bacteria-associated inhibition of apoptosis than A-class CpG-ODNs with the same modified oligoguanosines overhangs. The results of our study revealed that synthetic analogs of bacterial/host DNA, when phosphorothioate modified, can be used as inducers of reactive oxygen species generation by neutrophils. This allows to overcome the excess pro-survival effect caused by some pathogens, in particular Salmonella typhimurium, thus facilitating the successful resolution of inflammation. Ethics statement. The authors prepared neutrophils from the blood of healthy volunteers. Blood was collected via venous puncture, as approved by the Ministry of Public Health Service of the Russian Federation. Experimental and the subject consent procedures were approved by the Ethics Committee of the A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University. Fully informed consent was obtained, and all investigations were conducted according to the principles of the Declaration of Helsinki.

Granulocytes Acquire Antiapoptosis Activity and Promote Tumor Growth during Tumor Progress.

Granulocytes play important roles in cancer, and their apoptotic status is often changed by the influence of tumor environment. However, the changes and the function on granulocyte apoptosis in cancer are unclear. In this study, we used tumor-bearing mouse model and tumor patients to analyzed the apoptosis of granulocytes in different tissues by flow analysis and TUNEL fluorescence staining, and found that the percentage of apoptosis cells in granulocytes was significantly decreased in late-stage tumor-bearing mouse and patients. The in vitro co-culture experiment showed that these antiapoptotic granulocytes could significantly inhibit T cell proliferation, and RNA-seq proved that there was obvious difference on the transcriptome between these cells and control cells, particularly immune-related genes. What is important, adoptive transfer of these antiapoptotic granulocytes promoted tumor progress in mouse model. Conclusively, we found that granulocytes in late-stage tumor could delay the process of apoptosis, inhibit T cell proliferation, and acquire pro-tumor activity, which provides a new therapeutic target for tumor immunity.

Apoptosis of Eosinophil Granulocytes.

Simple SummaryEosinophil granulocytes (eosinophils) belong to the family of white blood cells that play important roles in the development of asthma and various types of allergy. Eosinophils are cells with a diameter of 12–17 µm and they originate from myeloid precursors. They were discovered by Paul Ehrlich in 1879 in the process of staining fixed blood smears with aniline dyes. Apoptosis (programmed cell death) is the process by which cells lose their functionality. Therefore, it is very important to study the apoptosis of eosinophils and their survival factors to understand how to develop new drugs based on the modulation of eosinophil apoptosis for the treatment of asthma and allergic diseases.In the past 10 years, the number of people in the Czech Republic with allergies has doubled to over three million. Allergic pollen catarrh, constitutional dermatitis and asthma are the allergic disorders most often diagnosed. Genuine food allergies today affect 6–8% of nursing infants, 3–5% of small children, and 2–4% of adults. These disorders are connected with eosinophil granulocytes and their apoptosis. Eosinophil granulocytes are postmitotic leukocytes containing a number of histotoxic substances that contribute to the initiation and continuation of allergic inflammatory reactions. Eosinophilia results from the disruption of the standard half-life of eosinophils by the expression of mechanisms that block the apoptosis of eosinophils, leading to the development of chronic inflammation. Glucocorticoids are used as a strong acting anti-inflammatory medicine in the treatment of hypereosinophilia. The removal of eosinophils by the mechanism of apoptosis is the effect of this process. This work sums up the contemporary knowledge concerning the apoptosis of eosinophils, its role in the aforementioned disorders, and the indications for the use of glucocorticoids in their related therapies.

Structural characteristics of circulating immune complexes in calves with bronchopneumonia: Impact on the quiescent leukocytes

Calf bronchopneumonia is accompanied by increased level of circulating immune complexes (CIC), and we analysed size, and protein and lipid constituents of these CIC with an attempt to elucidate the connection between the CIC structural properties and their capacity to modulate leukocyte function.CIC of heathy calves (CICH) and calves with naturally occurring bronchopneumonia (CICD) were isolated by PEG precipitation and analysed by electrophoresis and chromatography. The predominant CIC proteins were IgG, albumin, and transferrin. Affinity isolated serum and CIC IgG coprecipitated several proteins, but only 75 and 80 kDa proteins bound CIC IgG, exclusively. 60 and 65 kDa proteins co-precipitated with CICD IgG, unlike CICH IgG. In both CICH and CICD, oleic acid-containing phospholipids predominated. In CICD, the content of oleic and vaccenic acid was higher than in CICH, while myristic, palmitic, stearic, linoleic and arachidonic acid showed lower content. Dynamic light scattering displayed difference in particle size distribution between CICH and CICD; 1280 nm large particles were present only in CICD.The effect of CICH and CICD on mononuclear cells (MNC) and granulocytes was analysed in vitro. CICH and CICD, with slight difference in intensity, stimulate MNC apoptosis, promote cell cycle arrest of unstimulated MNC, and cell cycle progression of PHA stimulated MNC. Both CIC reduced granulocyte apoptosis after 24 h while after 48 h this effect was detected for CICD only.These results indicate that structural differences of CICH and CICD might interfere with the CIC functional capacity, which we consider important for evaluation of CIC immunoregulatory function.

Differential Effects of Dimethyl Fumarate and Monomethyl Fumarate on Neutrophil Granulocyte and PBMC Apoptosis

Fumaric acid ester (FAE) formulations are considered a first-line treatment for psoriasis and multiple sclerosis. Small case series and case reports document the use of FAE in various other, mostly granulomatous, diseases (Meissner et al., 2012). A common denominator of these clinically diverse diseases is that neutrophil granulocytes (polymorphonuclear neutrophils [PMNs]) and TNF-α signaling are thought to contribute to their pathogenesis (McCoy and Tansey, 2008; Nestle et al., 2009; Piette and Rosenbach, 2016).

Influence of Hyperglycemia During Different Phases of Ischemic Preconditioning on Cardioprotection-A Focus on Apoptosis and Aggregation of Granulocytes.

Ischemic preconditioning (IPC) protects the myocardium against ischemia/reperfusion injury. Evidence suggests that hyperglycemia inhibits IPC-induced cardioprotection. The effects of hyperglycemia initiated during different phases of IPC on myocardial injury were characterized with emphasis on apoptosis and aggregation of polymorphonuclear granulocytes (PMN). Male Wistar rats were subjected to 35 min of myocardial ischemia and 2 h of reperfusion. Control animals were not further treated. IPC was induced by three cycles of 3 min ischemia and 5 min of reperfusion before major ischemia. Hyperglycemia (blood glucose more than 22.2 mmol/L) was induced by glucose administration with or without IPC during different phases (trigger- (before ischemia), mediator- (during ischemia), early reperfusion-phase). One additional group received an anti-PMN-antibody before ischemia. Infarct size was quantified by triphenyltetrazolium chloride staining. Cytochrome C release and B-cell lymphoma two (Bcl-2) expression were assessed by western blot analysis. Poly-ADP-Ribose staining and PMN accumulation were quantified with immunohistochemistry and histochemistry. IPC reduced infarct size compared with control. Hyperglycemia completely abolished IPC-induced cardioprotection independent of the time point of initiation. Hyperglycemia before and during major ischemia but without IPC also slightly reduced infarct size. IPC reduced the accumulation of PMNs. This effect was reversed by hyperglycemia during trigger- and mediator-phase but not by hyperglycemia during reperfusion. Hyperglycemia alone had no effect on PMN accumulation. In all treatment groups, signs of myocardial apoptosis were reduced compared with control. IPC alone, combined with hyperglycemia and anti-PMN treatment, reduced apoptosis by a Bcl-2-associated mechanism. Hyperglycemia alone reduced apoptosis by a Bcl-2-independent pathway. Hyperglycemia inhibits IPC-induced cardioprotection independent of its onset. Furthermore, hyperglycemia prevents apoptosis and IPC-induced reduction of PMN aggregation.

Влияние пищевой добавки E407а на интенсивность апоптоза гранулоцитов в эксперименте in vitro

Влияние пищевой добавки E407а на интенсивность апоптоза гранулоцитов в эксперименте in vitro

Inflammation Resolution and the Induction of Granulocyte Apoptosis by Cyclin-Dependent Kinase Inhibitor Drugs.

Inflammation is a necessary dynamic tissue response to injury or infection and it's resolution is essential to return tissue homeostasis and function. Defective or dysregulated inflammation resolution contributes significantly to the pathogenesis of many, often common and challenging to treat human conditions. The transition of inflammation to resolution is an active process, involving the clearance of inflammatory cells (granulocytes), a change of mediators and their receptors, and prevention of further inflammatory cell infiltration. This review focuses on the use of cyclin dependent kinase inhibitor drugs to pharmacologically target this inflammatory resolution switch, specifically through inducing granulocyte apoptosis and phagocytic clearance of apoptotic cells (efferocytosis). The key processes and pathways required for granulocyte apoptosis, recruitment of phagocytes and mechanisms of engulfment are discussed along with the cumulating evidence for cyclin dependent kinase inhibitor drugs as pro-resolution therapeutics.