Frequency Of Apoptotic Cells Research Articles

Analysis of Cellular DNA Content by Flow Cytometry.

Cellular DNA content can be measured by flow cytometry with the aim of: (1) revealing cell distribution within the major phases of the cell cycle, (2) estimating frequency of apoptotic cells with fractional DNA content, and/or (3) disclosing DNA ploidy of the measured cell population. In this unit, simple and universally applicable methods for staining fixed cells are presented, as are methods that utilize detergents and/or proteolytic treatment to permeabilize cells and make DNA accessible to fluorochrome. Additionally, supravital cell staining with Hoechst 33342, which is primarily used for sorting live cells based on DNA-content differences for their subsequent culturing, is described. Also presented are methods for staining cell nuclei isolated from paraffin-embedded tissues. Available algorithms are listed for deconvolution of DNA-content-frequency histograms to estimate percentage of cells in major phases of the cell cycle and frequency of apoptotic cells with fractional DNA content. © 2017 by John Wiley & Sons, Inc.

Increased DNA damage and increased apoptosis and necrosis in patients with severe sepsis and septic shock

PurposeReactive oxygen species (ROS) has a key role in the pathogenesis of sepsis. We wanted to evaluate ROS-associated lymphocyte necrosis and apoptosis. Materials and methodsA total of 51 patients were included in the study, 29 in the patient group and 22 in the control group. Blood samples were taken from patients in the patient group during severe sepsis or septic shock, then again once they had recovered. Oxidative DNA damage was evaluated by 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels. Peripheral blood lymphocytes from patients were evaluated with a microscope immediately. The rate of apoptosis and necrosis of lymphocytes were evaluated according to the number of cells in the peripheral. ResultsThe level of 8-OHdG increased with severe sepsis or septic shock. There were significant differences between the pre- and post-treatment values for apoptotic cell frequency (4.21±3.15 vs. 3.82±3.07, P<0.05) and necrotic cell frequency (4.75±3.61 vs. 4.09±3.37, P<0.05). Apoptosis and necrosis was increased during severe sepsis and septic shock, and apoptosis increase also continued after recovery, but necrosis decreased following disease recovery. ConclusıonsIn patients with severe sepsis or septic shock, apoptosis and necrosis were increased along with increased 8-OHdG level.

Rac1-mediated cardiac damage causes diastolic dysfunction in a mouse model of subacute doxorubicin-induced cardiotoxicity.

The anticancer efficacy of anthracyclines is limited by congestive heart failure. Clinically established markers of early onset of cardiotoxicity following anthracycline treatment and preventive measures are missing. Although statins are reported to alleviate anthracycline-induced cardiotoxicity in vivo, the molecular mechanisms involved remain elusive. In vitro data point to Rac1 as major target of the cytoprotective statin effects. Here we investigated whether specific inhibition of Rac1 by NSC23766 is as effective as lovastatin in preventing subacute cardiotoxicity following doxorubicin treatment. C57BL/6 mice were treated over 3weeks with multiple low doses of doxorubicin (6×3mg/kgBW, i.p.) and the level of DNA damage, apoptosis and regenerative proliferation as well as pro-inflammatory, pro-fibrotic and oxidative stress responses were investigated. Moreover, heart function was monitored by echocardiography. Doxorubicin induced subacute cardiotoxicity which was reflected on the level of residual DNA damage, frequency of apoptotic and mitotic cells as well as elevated mRNA expression of markers of heart failure, remodeling and mitochondrial biogenesis. These molecular markers of cardiotoxicity were mitigated to a similar extent by co-treatment with either lovastatin (10mg/kgBW, p.o.) or NSC23766 (5mg/kgBW, i.p.) three times a week. Moreover, doxorubicin caused diastolic dysfunction as reflected by increased E-wave acceleration time (EAT), which again was prevented by pharmacological inhibition of Rac1. Inhibition of Rac1 signaling is of major relevance for the cardioprotective effects of lovastatin in the context of anthracycline-induced cardiotoxicity. Moreover, EAT is a useful marker of subacute cardiotoxicity caused by persisting harmful effects of doxorubicin.

High copper concentrations produce genotoxicity and cytotoxicity in bovine cumulus cells.

The aim of this study was to investigate the cytotoxic and genotoxic effects of high copper (Cu) concentrations on bovine cumulus cells (CCs) cultured in vitro. We evaluated the effect of 0, 120, 240, and 360μg/dL Cu added to in vitro maturation (IVM) medium on CC viability assessed by the trypan blue (TB)-fluorescein diacetate (FDA) and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assays, apoptosis, and DNA damage. Differences in cell viability assessed by TB-FDA were not significant among CC treated with 0, 120, 240, and 360μg/dL Cu. However, mitochondrial activity assessed by MTT was lower in CC cultured with 120, 240, and 360μg/dL Cu as compared with the control (p<0.01). Percentages of apoptotic cells were higher when CCs were treated with 120, 240, and 360μg/dL Cu (p<0.05) due to higher frequencies of late apoptotic cells (p<0.05). The frequency of live cells diminished in a dose-dependent manner when Cu was added to the culture medium. Whereas genetic damage index (GDI) increased significantly in CC cultured in the presence of 240 and 360μg/dL Cu (p˂0.05), DNA damage increased at all Cu concentrations tested (p˂0.05). These results indicate that Cu induces cytotoxic and genotoxic effects in bovine CC.

Selenium Antagonizes the Lead-Induced Apoptosis of Chicken Splenic Lymphocytes In Vitro by Activating the PI3K/Akt Pathway.

Lead (Pb) pollution has become one of the most serious global ecological problems. In animals, Pb ingestion induces apoptosis in many tissues. However, the mechanisms by which Pb induces apoptosis in chicken splenic lymphocytes in vitro via the PI3K/Akt pathway and the antagonistic effect of selenium (Se) on Pb remain unclear. Therefore, we established the in vitro Se-Pb interaction model in chicken splenic lymphocytes and examined the frequency of apoptotic cells using acridine orange/ethidium bromide (AO/EB) staining and the TdT-mediated dUTP nick end labeling assay and detected the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT), as well as the levels of malondialdehyde (MDA) and reactive oxygen species (ROS). The expression of PI3K/Akt pathway-related genes was also examined by qRT-PCR and western blotting. MDA and ROS levels were markedly increased, whereas the activities of GPx, SOD, and CAT were significantly decreased; the levels of the PI3K, Akt, and Bcl-2 messenger RNAs (mRNAs) and proteins were decreased; and the levels of the p53, Bax, cytochrome c (Cyt-c), caspase 3, and caspase 9 mRNAs and proteins were increased in the Pb group. In addition, the frequency of apoptotic cells was also significantly increased by the Pb treatment. However, Se supplementation during Pb exposure observably attenuated Pb-induced apoptosis; increased the levels of the PI3K, Akt, and Bcl-2 mRNAs and proteins; and decrease the levels of the p53, Bax, Cyt-c, caspase 3, and caspase 9 mRNAs and proteins in the chicken spleen. In conclusion, Pb exposure causes oxidative stress, inhibits the PI3K/Akt pathway, and subsequently induces apoptosis in chicken splenic lymphocytes in vitro, and these effects are partially attenuated by Se supplementation. To the best of our knowledge, this study is the first to reveal the antagonistic effect of Se on Pb-induced apoptosis of chicken splenic lymphocytes in vitro via the activation of the PI3K/Akt pathway.

168 Cardioprotective role of fingolimod in ischemia-reperfusion injury by activation of akt/erk pathways in rat model

Background and purposeIschaemic Heart Diseases (IHD) are the most common cause of morbidity and mortality. Incidence and prevalence are continuously growing. There is an escalating risk for revascularisation or resuscitation...

Graft-versus-Host Disease of the Gut: A Histologic Activity Grading System and Validation

The pathologic interpretation of gut biopsies in hematopoietic cell transplant recipients to assess graft-versus-host disease (GVHD) is well accepted and supplements clinical and endoscopic findings. However, the histologic activity grading of GVHD is controversial, with attempts to predict prognosis or response to treatment largely unsuccessful. GVHD is being diagnosed earlier in its course, raising the possibility that the pathologic grading system can be profitably modified. We developed a histologic activity grading system designed to replace the commonly used modified Lerner grading systems. Our system stratifies the low-level Lerner grade I category into 4 activity grade categories, based on the average frequency of apoptotic cells. The results are expressed as ordinal categories: GVHD of minimal, mild, moderate, severe histologic activity, or severe histologic activity with destruction (activity grades 1 to 5). In a retrospective study, we studied 87 consecutive cases with 201 post-transplantation specimens (median, 48 days; range, 18 to 1479 days) of stomach, duodenum, and colorectum, which had been activity graded at the time of the original diagnosis. Most of the biopsies diagnosed as GVHD were low grade—minimal (11%) or mild (71%) histologic activity. We hypothesized that the higher activity grades would be associated with more therapeutic intervention. The odds of increased therapy in the combined all-site specimens were increased as activity grade increased (odds ratio, 2.9 [95% confidence interval {CI}, 1.9 to 4.5]; P = < .0001). Thus, our grading system was validated. To investigate whether the activity grade was associated with therapy within the formerly undivided Lerner grade I category, the analysis was restricted to these 174 all-site specimens. The validation result was similar (odds ratio, 3.1 [95% CI, 1.3 to 7.2]; P = .009). This result interestingly suggests that there is useful information hidden in the Lerner grade I category, which could potentially guide immediately actionable treatment decisions. This histologic activity grade system has been in use at our institution for over 2 years with good acceptance.

An Increased Genotoxic Risk in Lymphocytes from Phototherapy-Treated Hyperbilirubinemic Neonates.

Background:Phototherapy is believed to be a safe method for the management of hyperbilirubinemia. However, there are some controversial issues regarding the genotoxic effects of phototherapy on DNA. The aim of this study was to investigate morphologically both phototherapy-induced DNA double-strand breaks (DSBs) and apoptosis in lymphocytes derived from jaundiced and non-jaundiced neonates.Methods:Newborns were divided into three groups, including phototherapy-treated (PT, n=30) jaundiced newborns with total serum bilirubin (TSB) levels >15 mg/dl, non-treated jaundiced newborns (C+, n=27), as positive, as well as healthy negative (C-, n=30) controls with TSB levels ranging from 10 and 15 mg/dl and less than 5 mg/dl, respectively. Lymphocytes were isolated from whole blood samples by Ficoll-isopaque density gradient centrifugation and then assessed for DNA damage and apoptosis before and 24 hours after incubation at 37°C in 5% CO2 using the neutral comet assay.Results:DSB levels were significantly much higher in the PT group compared to the controls before incubation but decreased remarkably after the incubation period. As expected, no statistical differences were found between the two control groups before and after incubations. The frequency of apoptotic cells showed no significant differences among all the three groups before incubation; however, it was significantly increased in the PT group after incubation.Conclusion:It seems that phototherapy in jaundiced infants is able not only to induce apoptosis in newborn lymphocytes but also to affect indirectly DNA integrity.

Effect of eicosapentaenoic acid on bovine cumulus-oocyte complex in vitro.

The aim of the present study was to investigate the effects of eicosapentaenoic acid (EPA) supplementation during in vitro maturation (IVM) of bovine oocytes. The concentrations tested in all experiments were 1 nM, 1 μM, and 1 mM EPA. The effect of EPA was evaluated on cumulus-oocyte complexes (COC) by oocyte maturation (cumulus expansion area and oocyte nuclear maturation), genotoxicity [single cell gel electrophoresis (SCGE)], and cytotoxicity (apoptosis, viability, and MTT assays) end points. The maturation parameters were affected by exposure of COC to different EPA concentrations in the IVM medium. Cumulus expansion area increased in the presence of 1 nM EPA (P < 0.05) whereas addition of 1 nM EPA (P < 0.05) decreased cumulus expansion after 24 h of IVM. Moreover, the maturation rate significantly decreased when 1 mM of EPA was assayed (P < 0.001). EPA at 1 nM induced genotoxic and cytotoxic effects on bovine cumulus cells (CC) and primary DNA lesions (P < 0.001). A significant increase in the frequency of apoptotic (P < 0.01) and necrotic (P < 0.001) cells was observed after 24 h of treatment with 1 nM, 1 μM, and 1 mM EPA. Mitochondrial activity was altered with 1 mM EPA (P < 0.001). We inferred that optimal oocyte quality was partially dependent on the presence of adequate EPA concentrations; EPA could be beneficial to improve oocyte quality in the maturation process, because low concentration tested (1 nM EPA) improved cumulus expansion.

Study the impact of astaxanthin on developing of genomic instability in human peripheral blood lymphocytes irradiated in vitro on G2 phase of cell cycle

To identify the possibility of modification by astaxanthin the level of genome damages induced by gamma quanta in the culture of human peripheral blood lymphocytes exposed in vitro on postsynthetic (G2) phase of the first mitotic cycle. Peripheral blood lymphocytes from four apparently healthy volunteers 35-51 years old were cultivated using modified micromethod. To obtain genomic damages in G2 phase of the first mitotic cycle the part of cultures was irradiated by γ quanta in dose 1.0 Gy through 46 hours of cultivation. Astaxanthin in final con centration 20 μg/ml was exposed to lymphocytes' cultures before the irradiation. Cytogenetic analysis the uniform ly stained slides of metaphase chromosomes was carried out to determine the frequencies of chromosome and chro matid types of aberrations. Using the method of individual cells electrophoresis (Comet assay) the relative level of DNA damages (Tail Moment index) and the frequency of apoptotic cells with high level of DNA fragmentation were evaluated. Mean group frequencies of chromosome aberrations after gamma irradiation of lymphocytes in vitro exceed ed those without radiation exposure and were 72.35 ± 1.17 and 2.46 ± 0.30 per 100 metaphases, respectively (p < 0.001), mainly due to chromatid type of aberrations (58.32 ± 1.29 per 100 metaphases). Adding of astaxanthin into culture medium before the irradiation did not result in changes as in the frequency of chromosomal damages (71.54 ± 1.34 per 100 metaphases) as in the spectrum of aberrations - also prevailed chromatid type of aberrations (58.47 ± 1.47 per 100 metaphases). The increase of Tail Moment index after radiation exposure (from 3.84 ± 0.36 to 12.06 ± 1.88, respectively, p < 0.001) and lack of significant impact of astaxanthin on this index in the irradiated lym phocytes (8.96 ± 2.39, p > 0.05) was established, ie astaxanthin didn't change the relative level of radiation induced DNA damages. Also apoptogenic effect of astaxanthin was not found: frequency of apoptotic cells were (2.25 ± 1.49) % in cultures of intact lymphocytes, (2.08 ± 1.54) % in irradiated cultures and (1.78 ± 1.25) % under joint action of gamma radiation and astaxanthin (p > 0.05). Noimpactofastaxanthinongenomicinstabilityinducedbygammairradiation invitroinculturesof human peripheral blood lymphocytes on postsynthetic (G2) phase of first mitotic cycle had been established.

Fluorochrome-Labeled Inhibitors of Caspases: Expedient In Vitro and In Vivo Markers of Apoptotic Cells for Rapid Cytometric Analysis.

Activation of caspases is a characteristic event of apoptosis. Various cytometric methods distinguishing this event have been developed to serve as specific apoptotic markers for the assessment of apoptotic frequency within different cell populations. The method described in this chapter utilizes fluorochrome labeled inhibitors of caspases (FLICA) and is applicable to fluorescence microscopy, flow- and imaging-cytometry as well as to confocal imaging. Cell-permeant FLICA reagents tagged with carboxyfluorescein or sulforhodamine, when applied to live cells in vitro or in vivo, exclusively label the cells that are undergoing apoptosis. The FLICA labeling methodology is rapid, simple, robust, and can be combined with other markers of cell death for multiplexed analysis. Examples are presented on FLICA use in combination with a vital stain (propidium iodide), detection of the loss of mitochondrial electrochemical potential, and exposure of phosphatidylserine on the outer surface of plasma cell membrane using Annexin V fluorochrome conjugates. FLICA staining followed by cell fixation and stoichiometric staining of cellular DNA demonstrate that FLICA binding can be correlated with the concurrent analysis of DNA ploidy, cell cycle phase, DNA fragmentation, and other apoptotic events whose detection requires cell permeabilization. The "time window" for the detection of apoptosis with FLICA is wider compared to the Annexin V binding, making FLICA a preferable marker for the detection of early phase apoptosis and therefore more accurate for quantification of apoptotic cells. Unlike many other biomarkers of apoptotic cells, FLICAs can be used to detect apoptosis ex vivo and in vivo in different tissues.

Mesenchymal Stromal Cells Expressing Interferon α Limit the Development of Acute Myeloid Leukemia, Inducing Apoptosis In Vitro and In Vivo

IntroductionThe 5-year survival for patients with acute myeloid leukemia (AML) has stagnated for over two decades at about 60% for children, 40% for young adults, and <15% for elderly patients. While most patients achieve remission, approximately 50% will relapse which is generally attributed to the persistence of leukemic stem cells. Interferon α (IFNα) is an effective therapy for patients with AML due to multiple mechanisms of action. However, high serum levels are associated with many adverse effects. In this proof-of-concept study, we used engineered mesenchymal stem/stromal cells (MSC) to deliver high concentrations of IFNα locally to an AML chloroma, potentially diminishing the poorly tolerated systemic side-effects.MethodsBone marrow MSCs from C57BL/6 mouse were isolated and transduced with a lentiviral vector expressing murine IFNα (IFNα-MSCs) and/or GFP (GFP MSCs). After measuring IFNα secretion by ELISA and confirming activity by the induction of the MHC I expression on the transduced cells, the anti-AML activity of these transduced MSCs was assessed by co-culture with the C57BL/6 AML cell line c1498 which expresses DsRed and firefly luciferase (FFluc). Apoptotic cell frequencies and cell cycle phase distributions of leukemia cells with or without MSCs were assessed by flow cytometry. The in vivo validation has been performed by subcutaneous injection of c1498 cells (chloroma) with or without GFP MSCs or IFNα MSCs in C57BL/6 mice. Tumor growth was monitored by bioluminescence imaging every 3 or 4 days.ResultsFlow cytometric analysis and ELISA confirmed the secretion of bio-active of IFNα by transduced MSCs (41.5 ng/1E06 MSCs/24h). In co-cultures, the presence of IFNα MSCs at the ratio 100:1 (c1498: MSC) significantly decreased the population of c1498 cells mainly by inducing apoptosis compared to MSC-free or GFP MSC co-cultures while no effect was observed on cell cycle distribution. The pro-apoptotic effect of IFNα MSCs was then investigated in vivo by subcutaneous injection of c1498 cells with or without MSCs (ratio 10:1) in C57BL/6 mice.The presence of IFNα MSCs significantly decreased leukemic cell mass as shown by the bioluminescence of the DsRed+ FFLuc+ c1498 cells. This result was confirmed by flow cytometric analysis of the percentage of DsRed + cells in the chloroma.ConclusionsThis study shows that IFNα MSCs present a strong anti-leukemic effect in vitro and in vivo promoting apoptosis and thus decreasing the leukemic burden. Further experiments will focus on a potential synergetic effect with Cytarabine treatment and a preclinical study using human IFNα MSCs in a xenograft murine model. DisclosuresNo relevant conflicts of interest to declare.

The Focal Adhesion Complex Ilk-Pinch-Parvin Is Key to Niche Interactions and Survival of Quiescent Stem Cells in Chronic Myeloid Leukemia In Vitro and In Vivo

Growing evidence indicates that interactions of cancer cells with their microenvironment in vivo can influence disease progression and therapy resistance, including chronic myeloid leukemia (CML). Focal adhesions that modulate cell attachments, migration, proliferation and intracellular signaling pathways are considered critical mediators of some of these interactions. However, the potential role of focal adhesion components in mediating survival and therapeutic responses of leukemic stem cells is largely unknown.Transcriptional profiling of CD34+ cells from 6 CML patients and 3 healthy donors revealed that the expression of Integrin-linked kinase (ILK), PINCH1 and β-Parvin, major constituents of focal adhesions, is significantly increased in CD34+ CML cells, in particular in cells from drug-nonresponders (p<0.05). Quantitative real-time PCR confirmed these observations in CD34+ cells obtained from additional 30 CML patients and 14 normal healthy adults (p<0.05). Furthermore, we found that the primitive leukemic stem-cell enriched Lin-CD34+CD38- portion from CML patients expressed the highest levels of ILK, PINCH1, and β-Parvin transcripts compared to the more prevalent Lin-CD34+CD38+ progenitor population or mature CD34-cells in the same samples (n=6, p<0.05). In addition, ILK protein expression was increased in primitive CML cells compared to normal donors, in particular when CML cells were co-cultured with BM niche cells.Stable knockdown (KD) of 3 different targeting sequences of ILK in CD34+ CML cells resulted in decreased cell viability (30-80%, p<0.05) and proliferation (2-12-fold) associated with a significantly enhanced frequency of apoptotic cells compared to control-transduced cells (60-80% vs. 30%, p<0.05). Interestingly, these effects of ILK KD were not rescued by co-cultures with BM niche cells in vitro. Cell cycle analysis indicated a reduction in the proportion of surviving cells in S-phase upon ILK suppression. In addition, Western blotting showed that effective suppression of ILK led also to a decrease in β-Parvin and PINCH1 protein expression but not their transcript levels, suggesting that the ILK-PINCH-PARVIN complex is not stable under these conditions and may not be able to mediate critical interactions between primitive CML cells and BM niche components. In agreement, short- and long-term assays of stem/progenitor activity in the presence of BM niche cells demonstrated a significant reduction of colonies upon ILK suppression that was almost entirely abolished with simultaneous ABL1 tyrosine kinase inhibitor (TKI) treatment (p<0.05). Moreover, in vivo studies with 2 different mouse strains (NRG and the humanized NRG-3GS model) emphasized that primitive ILK KD CML cells showed greatly reduced in vivo regenerative activity as compared to control-transduced cells (<2% vs. 13% human cells in the BM of NRG mice, and 3% vs. 18% in NRG-3GS mice 25 weeks post-transplantation).To investigate whether ILK can be targeted pharmacologically, we utilized QLT0267, a validated and selective ILK kinase inhibitor. Similarly to ILK suppression, inhibition of the ILK kinase resulted in a modest decrease of cell viability, reduced short-and long-term stem/progenitor activity, and increased apoptosis of bulk CD34+ as well as more primitive Lin-CD34+CD38- CML cells from drug-nonresponder patients with strong synergistic effects upon simultaneous ABL1 kinase inhibition in vitro. In addition, oral gavage of QLT0267 combined with dasatinib significantly enhanced survival of leukemic mice and eradicated infiltrated leukemic cells in multiple hematopoietic tissues in an aggressive NSG mouse model of BCR-ABL+human leukemia. Most interestingly, dual inhibition of ILK and BCR-ABL1 decreased the proportion of quiescent leukemic stem cells compared to single agent treatments. RNA sequencing of these cells indicated a deregulation of MYC and novel signaling targets, with differences between dividing and non-dividing cell subpopulations.In summary, genetic and pharmacological inhibition of ILK significantly impaired survival, proliferation and quiescence of drug-nonresponder CML stem cells and sensitized them to TKIs both in vitro and in vivo. These findings suggest that ILK plays a critical role in regulating CML stem cell activity and that targeting ILK and BCR-ABL1 simultaneously may offer an improved novel therapeutic strategy. DisclosuresNo relevant conflicts of interest to declare.

Multi-biomarker investigation to assess toxicity induced by two antidepressants on Dreissena polymorpha

Antidepressants are one of the main pharmaceutical classes detected in the aquatic environment. Nevertheless, there is a dearth of information regarding their potential adverse effects on non-target organisms. Thus, the aim of this study was the evaluation of sub-lethal effects on the freshwater mussel Dreissena polymorpha of two antidepressants commonly found in the aquatic environment, namely Fluoxetine (FLX) and Citalopram (CT). D. polymorpha specimens were exposed to FLX and CT alone and to their mixture (MIX) at the environmental concentration of 500ng/L for 14days. We evaluated the sub-lethal effects in the mussel soft tissues by means of a biomarker suite: the activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and the activity of the phase II detoxifying enzyme glutathione-S-transferase (GST). The oxidative damage was evaluated by lipid peroxidation (LPO) and protein carbonylation (PCC), while genetic damage was tested on D. polymorpha hemocytes by Single Cell Gel Electrophoresis (SCGE) assay, DNA diffusion assay and micronucleus test (MN test). Finally, the functionality of the ABC transporter P-glycoprotein (P-gp) was measured in D. polymorpha gills. Our results highlight that CT, MIX and to a lesser extent FLX, caused a significant alteration of the oxidative status of bivalves, accompanied by a significant reduction of P-gp efflux activity. However, only FLX induced a slight, but significant, increase in apoptotic and necrotic cell frequencies. Considering the variability in biomarker response and to perform a toxicity comparison of tested molecules, we integrated each endpoint into the Biomarker Response Index (BRI). The data integration showed that 500ng/L of FLX, CT and their MIX have the same toxicity on bivalves.

Evaluation of genotoxicity and antioxidant enzymes in women occupationally exposed to pesticides

Temephos is an organophosphorus pesticide that is used in control campaigns against Aedes aegypti mosquitoes, which transmit dengue. In spite of the widespread use of temephos, few studies have examined its genotoxic potential. The aim of this study was to evaluate the cytotoxic, cytostatic and genotoxic effects of temephos in human lymphocytes and hepatoma cells (HepG2). The cytotoxicity was evaluated with simultaneous staining (FDA/EtBr). The cytostatic and genotoxic effects were evaluated using comet assays and the micronucleus technique. We found that temephos was not cytotoxic in either lymphocytes or HepG2 cells. Regarding the cytostatic effect in human lymphocytes, temephos (10 μM) caused a significant decrease in the percentage of binucleated cells and in the nuclear division index as well as an increase in the apoptotic cell frequency, which was not the case for HepG2 cells. The comet assay showed that temephos increased the DNA damage levels in human lymphocytes, but it did not increase the MN frequency. In contrast, in HepG2 cells, temephos increased the tail length, tail moment and MN frequency in HepG2 cells compared to control cells. In conclusion, temephos causes stable DNA damage in HepG2 cells but not in human lymphocytes. These findings suggest the importance of temephos biotransformation in its genotoxic effect.

Effects of environmental radiation on testes and spermatogenesis in wild large Japanese field mice (Apodemus speciosus) from Fukushima.

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident that occurred after the Great East Japan Earthquake in March 2011 released large quantities of radionuclides to the environment. The long-term effects of radioactive cesium (Cs) on biota are of particular concern. We investigated the accumulation of radioactive Cs derived from the FDNPP accident, and chronic effects of environmental radionuclides on male reproduction, in the large Japanese field mouse (Apodemus speciosus). In 2013 and 2014, wild mice were captured at 2 sites in Fukushima Prefecture and at 2 control sites that were distant from Fukushima. Although the median concentrations of 134Cs and 137Cs in the mice from Fukushima exceeded 4,000 Bq/kg, there were no significant differences in the apoptotic cell frequencies or the frequencies of morphologically abnormal sperm among the capture sites. Thus, we conclude that radiation did not cause substantial male subfertility in Fukushima during 2013 and 2014, and radionuclide pollution levels in the study sites would not be detrimental to spermatogenesis of the wild mice in Fukushima.

Ptpn22 Modifies Regulatory T Cell Homeostasis via GITR Upregulation.

PTPN22 gene variation associates with multiple autoimmune diseases, including type 1 diabetes and rheumatoid arthritis. Loss of function studies have demonstrated that PTPN22 impinges on the homeostatic behavior of regulatory T (Treg) cells, a lineage critical for immune tolerance. The frequency and absolute number of Treg cells is increased in Ptpn22-deficient mice, but the mechanism driving this increase is unknown. In this study, we show that Ptpn22 knockdown (KD) promoted the expansion of the Treg cell compartment by upregulating the glucocorticoid-induced TNFR family-related protein (GITR) and increasing GITR signaling. Ptpn22 KD did not accelerate cell division but instead prolonged Treg cell survival, as measured by a decrease in the frequency of apoptotic Treg cells. Loss of Ptpn22 caused a concomitant increase in the proportion of CD44(hi)CD62L(lo) effector Treg cells, at the expense of CD44(lo)CD62L(hi) central Treg cells. The increase in Treg cell numbers, but not their differentiation toward an effector phenotype, was dependent on GITR signaling, because blockade of GITR ligand prevented Treg cell expansion caused by Ptpn22 KD. These findings indicate that GITR plays a key role in regulating the overall size of the Treg cell pool. Our results suggest that the size and composition of the Treg cell compartment are independently controlled and have implications for the design of immunotherapies that seek to improve Treg cell function.

Activation of TIM1 induces colon cancer cell apoptosis via modulating Fas ligand expression

The pathogenesis of colon cancer is unclear. It is proposed that TIM1 has an association with human cancer. The present study aims to investigate the role of TIM1 activation in the inhibition of human colon cancer cells. In this study, human colon cancer cell line, HT29 and T84 cells were cultured. The expression of TIM1 was assessed by real time RT-PCR and Western blotting. The TIM1 on the cancer cells was activated in the culture by adding recombinant TIM4. The chromatin structure at the FasL promoter locus was assessed by chromatin immunoprecipitation. The apoptosis of the cancer cells was assessed by flow cytometry. The results showed that human colon cancer cell lines, HT29 cells and T84 cells, expressed TIM1. Activation of TIM1 by exposing the cells to TIM4 significantly increased the frequency of apoptotic colon cancer cells. The expression of FasL was increased in the cancer cells after treating by TIM4. Blocking Fas or FasL abolished the exposure to TIM4-induced T84 cell apoptosis. In conclusion, HT29 cells and T84 cells express TIM1; activation TIM1 can induce the cancer cell apoptosis. TIM1 may be a novel therapeutic target of colon cancer.

Overexpression of PRL7D1 in Leydig Cells Causes Male Reproductive Dysfunction in Mice.

Prolactin family 7, subfamily d, member 1 (PRL7D1) is found in mouse placenta. Our recent work showed that PRL7D1 is also present in mouse testis Leydig cells, and the expression of PRL7D1 in the testis exhibits an age-related increase. In the present study, we generated transgenic mice with Leydig cell-specific PRL7D1 overexpression to explore its function during male reproduction. Prl7d1 male mice exhibited subfertility as reflected by reduced sperm counts and litter sizes. The testes from Prl7d1 transgenic mice appeared histologically normal, but the frequency of apoptotic germ cells was increased. Prl7d1 transgenic mice also had lower testosterone concentrations than wild-type mice. Mechanistic studies revealed that Prl7d1 transgenic mice have defects in the testicular expression of steroidogenic acute regulatory protein (STAR) and hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase cluster (HSD3B). Further studies revealed that PRL7D1 overexpression affected the expression of transferrin (TF) in Sertoli cells. These results suggest that PRL7D1 overexpression could lead to increased germ cell apoptosis and exert an inhibitory effect on testosterone production in Leydig cells by reducing the expression of certain steroidogenic-related genes. In addition, PRL7D1 appears to have important roles in the function of Sertoli cells, which, in turn, affects male fertility. We conclude that the expression level of PRL7D1 is associated with the reproductive function of male mice.

Particular activation phenotype of T cells expressing HLA-DR but not CD38 in GALT from HIV-controllers is associated with immune regulation and delayed progression to AIDS.

The spontaneous control of HIV replication in HIV-controllers underlines the importance of these subjects for exploring factors related to delayed progression. Several studies have revealed fewer immune alterations and effector mechanisms related to viral control, mainly in peripheral blood, in these individuals compared to normal progressors. However, immune characterization of gut-associated lymphoid tissue (GALT), the major target of infection, has not been thoroughly explored in these subjects. We evaluated the following parameters in GALT samples from 11 HIV-controllers and 15 HIV-progressors: (i) frequency and activation phenotype of T cells; (ii) expression of transcription factors associated with immune response profiles; and (iii) frequency of apoptotic cells. Interestingly, HIV-controllers exhibited a particular activation phenotype, with predominance of T cells expressing HLA-DR but not CD38 in GALT. This phenotype, previously associated with better control of infection, was correlated with low viral load and higher CD4(+) T cell count. Furthermore, a positive correlation of this activation phenotype with higher expression of Foxp3 and RORγT transcription factors suggested a key role for Treg and Th17 cells in the control of the immune activation and in the maintenance of gut mucosal integrity. Although we evaluated apoptosis by measuring expression of cleaved caspase-3 in GALT, we did not find differences between HIV-controllers and HIV-progressors. Taken together, our findings suggest that predominance of HLA-DR(+) T cells, along with lower immune activation and higher expression of transcription factors required for the development of Treg and Th17 cells, is associated with better viral control and delayed progression to AIDS.