Annexin-V Research Articles

Rutin enhances mitochondrial function and improves the developmental potential of vitrified ovine GV-stage oocyte

Vitrification of oocyte has become an important component of assisted reproductive technology and has important implications for animal reproduction and the preservation of biodiversity. However, vitrification adversely affects mitochondrial function and oocyte developmental potential, mainly because of oxidative damage. Rutin is a highly effective antioxidant, but no information is available to the effect of rutin on the mitochondrial function and development in vitrified oocytes. Therefore, we studied the effects of rutin supplementation of vitrification solution on mitochondrial function and developmental competence of ovine germinal vesicle (GV) stage oocytes post vitrification. The results showed that supplementation of vitrification solution with 0.6 mM rutin significantly increased the cleavage rate (71.6 % vs. 59.3 %) and blastocyst rate (18.9 % vs. 6.8 %) compared to GV-stage oocytes in the vitrified group. Then, we analyzed the reactive oxygen species (ROS), glutathione (GSH), mitochondrial activity and membrane potential (ΔΨm), endoplasmic reticulum (ER) Ca2+, and annexin V (AV) of vitrified sheep GV-stage oocytes. Vitrified sheep oocytes exhibited increased levels of ROS and Ca2+, higher rate of AV-positive oocytes, and decreased mitochondrial activity, GSH and ΔΨm levels. However, rutin supplementation in vitrification solution decreased the levels of ROS, Ca2+ and AV-positive oocytes rate, and increased the GSH and ΔΨm levels in vitrified oocytes. Results revealed that rutin restored mitochondrial function, regulated Ca2+ homeostasis and decreased apoptosis potentially caused by mitophagy in oocytes. To understand the mechanism of rutin functions in vitrified GV-stage oocytes in sheep, we analyzed the transcriptome and found that rutin mediated oocytes development and mitochondrial function, mainly by affecting oxidative phosphorylation and the mitophagy pathways. In conclusion, supplementing with 0.6 mM rutin in vitrification solution significantly enhanced developmental potential through improving mitochondrial function and decreased apoptosis potentially caused by mitophagy after vitrification of ovine GV-stage oocytes.

Relation between interleukin-13 and annexin-V levels and carotid intima-media thickness in nephrotic syndrome.

The aim of the current study is to assess the relation between carotid intima-media thickness (CIMT) measurements, renal Doppler resistive index (RI) and serum levels of interleukin-13 (IL-13) and annexin-V (An-V) in children with idiopathic nephrotic syndrome (INS). The present case-control study was conducted on 60 children with INS and 60 age- and sex-matched healthy children. All participants were subjected to evaluation of serum levels of IL-13 and An-V and ultrasound Doppler measurement of CIMT and renal RI. Patients expressed significantly higher An-V (5.9 ± 2.6 vs. 2.1 ± 0.8 ng/mL, p<0.001) and IL-13 (19.2 ± 7.6 vs. 3.4 ± 1.4 ng/L) levels when compared with healthy counterparts. Moreover, it was shown that patients had significantly higher CIMT (0.49 ± 0.06 vs. 0.35 ± 0.03, p<0.001) as compared to controls. No significant differences were noted between the studied groups regarding right or left RIs. Correlation analysis identified significant direct correlation between serum An-V levels and albumin/creatinine ratio (ACR) (r = 0.55), cholesterol (r = 0.48), triglycerides (r = 0.36), IL-13 (r = 0.92) and CIMT (r = 0.53). Similar correlations could be found between serum IL-13 levels and CIMT measurements and the corresponding parameters. The present study suggests an association between higher early atherosclerosis expressed as elevated CIMT measurements in children with INS and elevated serum levels of An-V and IL-13.

“In House” assays for the quantification of Annexin V and its autoantibodies in patients with recurrent pregnancy loss and in vitro fertilisation failures

Several studies have been shown that Annexin V (ANXV) autoantibodies concentrations are associated with both early recurrent pregnancy losses (RPLs) or in vitro fertilization failure (IVFf). We investigated the association between ANXV autoantibodies and ANVX levels in RPL, IVFf and normal group women. The study was conducted on 22 female patients with RPLs, 66 patients with IVFf, and 16 normal samples from women who had given birth. ANXV autoantibodies were measured using an ELISA test developed by fixing a homemade recombinant ANXV protein and examined with labeled human antibodies, while ANXV concentrations were measured by a competitive ELISA using a homemade anti ANXV polyclonal antibody. The results showed a clear relationship between the high levels of ANXV autoantibodies and the recurrent abortion. On the other hand, ANXV measurement in those patients showed decreased concentrations compared to normal samples. Negative correlation between ANXV and its autoantibodies levels was reported in almost all patients’ samples. Our data supports the possibility that ANXV autoantibodies are a risk factor for reproductive failures associated with both RPLs and/or IVFf and the significant role for ANXV in the maintenance of pregnancy.

Sevoflurane-mediated modulation of oxidative myocardial injury.

Volatile anesthetics offer protection when administered throughout an ischemic injury. We examined how volatile anesthetics modulate the cardiac myocytic injury associated with hydrogen peroxide. Forty-eight Long-Evans rats were divided into four groups depending on the treatment: none (CONT), Glibenclamide (GLB); Sevoflurane (SEV); or GLB+SEV. Each group was further divided into two, one of which was exposed to hydrogen peroxide (H2O2). Oral GLB was administered 48 hours before myocardial isolation. All rats were anesthetized by intraperitoneal injection of Ketamine, and the hearts were harvested after heparinization. Cardiomyocytes were isolated using a combination of mechanical mincing and enzymatic digestion. After isolation, the aliquots of cells were exposed to H2O2 and FeSO4 for 30 minutes. The cell suspensions were then bubbled for 10 minutes with 100% oxygen and 1.5% SEV if appropriate. Apoptosis was detected by fluorescein-bound annexin-V (ANX-V), necrosis by propidium iodide, and ELISA assessed caspase-3 activity in all groups. There was an increase in apoptosis, necrosis, and caspase-3 activity in the cells following exposure to hydrogen peroxide. SEV reduced the rate of cell necrosis and apoptosis. Pretreatment with GLB did not alter the effects of SEV. Similarly, caspase-3 activity did not change with GLB, although SEV administration reduced this enzymatic activity in response to hydrogen peroxide. In this oxidant injury model, we demonstrated that incubating isolated cardiomyocytes with SEV profoundly diminished H2O2-induced apoptotic and necrotic cells compared to their CONTs. These results support the hypothesis that KATP channels are not the sole mediators associated with anesthetic preconditioning.

Platelet-Released Extracellular Vesicle Characteristics Differ in Chronic and in Acute Heart Disease.

Extracellular vesicles (EVs), shed in response to cell activation, stress, or injury, are increased in the blood of patients with cardiovascular disease. EVs are characterized by expressing parental-cell antigens, allowing the determination of their cellular origin. Platelet-derived EVs (pEVs) are the most abundant in blood. Although not universally given, EVs generally express phosphatidylserine (PS) in their membrane. To investigate pEVs in chronic and acute conditions, such as chronic heart failure (CHF) and first-onset acute coronary syndrome (ACS), in patients treated as per guidelines. EVs in CHF patients (n = 119), ACS patients (n = 58), their respective controls (non-CHF [n = 21] and non-ACS [n = 24], respectively), and a reference control group (n = 31) were characterized and quantified by flow cytometry, using monoclonal antibodies against platelet antigens, and annexin V (AV) to determine PS exposure. CHF patients had higher EVs-PS- numbers, while ACS had predominantly EVs-PS+. In contrast to ACS, CHF patients had significantly reduced numbers of pEVs carrying PECAM and αIIb-integrin epitopes (CD31+/AV+, CD41a+/AV+, and CD31+/CD41a+/AV+), while no differences were observed in P-selectin-rich pEVs (CD62P+/AV+) compared with controls. Additionally, background etiology of CHF (ischemic vs. nonischemic) or ACS type (ST-elevation myocardial infarction [STEMI] vs. non-STEMI [NSTEMI]) did not affect pEV levels. PS exposure in EV and pEV-release differ between CHF and ACS patients, with tentatively different functional capacities beyond coagulation to inflammation and cross-talk with other cell types.

Vitamin D Receptor Regulates Autophagy to Inhibit Apoptosis and Promote Proliferation in Hepatocyte Injury.

Oxidative stress is an important mechanism in liver ischemia/reperfusion (I/R) injury. Hepatocyte apoptosis and proliferation occur in parallel with liver I/R injury, and the degree of apoptosis and proliferation determines the effects on hepatocytes. Vitamin D receptor (VDR) can lessen liver I/R injury, but previous studies focused mostly on inflammation and immunity. H2O2 was used to induce hepatocyte injury. Before treatment with H2O2, Hep-3B cells were pretreated with paricalcitol (PC) and siRNA-VDR. Rapamycin and chloroquine were also applied in the study. The number of apoptotic cells was measured with an annexin V (AV) -fluorescein isothiocyanate apoptosis detection kit. Expression of proteins was measured by western blotting. As compared with the H2O2+Hep-3B group, levels of AV/PI, cleaved caspase-3, and p62 were lower, and expression levels of Bcl-2, proliferating cell nuclear antigen, and VDR were higher, in the PC+H2O2+Hep-3B group. When the VDR gene was silenced by siRNA-VDR in the siRNA-VDR+H2O2+Hep-3B group, expressions of AV/PI, cleaved caspase-3, and p62 were upregulated, and expressions of Bcl-2, proliferating cell nuclear antigen, and VDR were downregulated, as compared with values for the siRNA-NC+H2O2+Hep-3B group. Treatment with rapamycin or chloroquine partially reversed the effect of PC and siRNA-VDR on apoptosis and proliferation. VDR mediates hepatocyte apoptosis and proliferation through autophagy.

Anti-Cancer Effects of Queen Bee Acid (10-Hydroxy-2-Decenoic Acid) and Its Cellular Mechanisms against Human Hepatoma Cells

Hepatocellular carcinoma (HCC) is the most common form of liver cancer that occurs in hepatocytes. Although many chemical drugs, e.g., cisplatin, methotrexate, taxis, and doxorubicin are used to treat HCC, there have been numerous reports related to the side effects of these drugs (e.g., emerging drug resistance, bone marrow failure, and gastrointestinal disorders). These issues led scientists to search for the novel anti-cancer drugs, mainly in natural products with greater efficiency and less toxicity. The current survey was intended to assess the anti-cancer effects of queen bee acid (10-Hydroxy-2-Decenoic Acid, 10-HDA) and its cellular mechanisms against the human hepatoma cell line HepG2. The MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay was used to evaluate the effect of 10-HDA on the viability of HepG2 cells. The initial and late apoptosis in the HepG2 cells treated with 10-HDA were assessed by the Annexin-V (AV) assay. The level of the gene and protein expression of some apoptosis genes (e.g., caspase-3, Bcl-2-associated X protein (BAX), and B-cell lymphoma protein 2 (Bcl-2)), Poly (ADP-ribose) polymerases (PARP), and miRNA-34a (miR-34a), were measured by real-time PCR and Western blot. The obtained findings revealed that HepG2 cell viability was markedly reduced (p < 0.01) following exposure to 10-HDA in a dose-dependent matter. The calculated half maximal cytotoxic concentration (CC50) value of 10-HDA was 59.6 µg/mL for HepG2 cells, while this value for normal THLE-3 cells was 106.4 µg/mL. We found that 10-HDA markedly elevated (p < 0.01) the percentage of necrotic and apoptotic cells from 0.94 to 9.7 and 27.6%, respectively. The real-time PCR results showed that the expression levels of the caspase-3, Bax, and miR-34a genes were significantly (p < 0.001) elevated. Contrary to these results, a significant (p < 0.01) reduction in the expression level of the Bcl2 gene was observed. The levels of protein expression of Caspase-3, PARP, and Bax were markedly elevated following exposure of HepG2 cells to 10-HDA at ¼ CC50, ½ CC50, and CC50. The level of protein expression of Bcl-2 was markedly reduced following exposure of HepG2 cells to 10-HDA at ¼ CC50, ½ CC50, and CC50 (p < 0.01). The current results confirmed the potent in vitro cytotoxic effects of 10-HDA on HepG2 cells with no significant cytotoxic effects on normal cells. Although its mechanisms of action have not been fully studied, the induction of apoptosis via different pathways was determined as one of the principle mechanisms of action of 10-HDA against HepG2 cells. Nevertheless, additional surveys must be performed to clearly understand the mechanisms of action and safety of this fatty acid.

Антифосфолипидные антитела и исходы программ вспомогательных репродуктивных технологий у пациенток с СOVID-19 в анамнезе

Investigation of the effect COVID-19 mediated with autoantibodies has on reproductive outcomes is important. This study aimed to evaluate the profile of antiphospholipid antibodies (aPL) and their association with the outcomes of assisted reproductive technology (ART) programs in patients with a history of COVID-19. The study included 240 patients: 105 of them did not have a history of COVID-19 (group 1) and 135 of them had a history of COVID-19 (group 2) with a mild course (subgroup 2a, n = 85) or moderate course (subgroup 2b, n = 50). With the help of ELISA, serum antibodies (M, G) to cardiolipin, β2-glycoprotein-I, annexin V (AnV), phosphatidylethanolamine (PE), phosphatidylserine, and phosphatidylserine/prothrombin complex were determined. The evaluated parameters were the indices of oogenesis, embryogenesis, ART intervention outcomes. In group 2, growing levels of anti-AnV and anti-PE IgG were observed more often (in 28 (20.7%) and 8 (5.9%) patients) than in group 1 (in 10 (9.5%) and 1 (0.95%); p = 0.02 and p = 0.045, respectively). In subgroup 2b we registered a higher level of anti-PE IgG and a higher incidence of early miscarriages (in 6 (12%) patients) than in group 1 (in 3 (2.9%)) (p = 0.024). Weak inverse correlations were found between the level of anti-PE IgG and the number of oocytes and zygotes. The results of this study suggest a negative impact of aPL-mediated COVID-19 on the outcomes of ART programs and the course of early pregnancy.

Changes in glycans on platelet microparticles released during storage of apheresis platelets are associated with phosphatidylserine externalization and phagocytosis.

Platelets shed platelet microparticles (PMP) when activated or stored. As the removal of sialic acid (desialylation) promotes platelet uptake and clearance from the circulation, similar mechanisms for PMP uptake were hypothesized. The aim of the study was to investigate the role of surface glycans in the in vitro uptake of PMP from stored platelet components. Apheresis platelet components were stored in 40% plasma/60% SSP+ and sampled on day 1, 5, and 7 post-collection. PMP were characterized by staining with annexin-V (AnV) for phosphatidylserine (PS)-exposure, CD41 antibody, and fluorescently labeled glycan-binding lectins using flow cytometry. The procoagulant function of PMP following desialylation by neuraminidase treatment was assessed by AnV binding and a procoagulant phospholipid assay. PMP were isolated and stained with Deep Red, and phagocytosis by HepG2 cells was measured. Isolated PMP were deglycosylated with neuraminidase and galactosidase to assess the involvement of glycans in mediating phagocytosis. While the overall platelet surface glycan profile was unchanged during storage, PS+ platelets were sialylated, indicating different glycoproteins were changed. In contrast, sialic acid was removed from PS+ and CD41+ PMP, which specifically lost α-2,3-linked sialic acid during platelet storage. PMP were phagocytized by HepG2 cells, and PMP from platelets stored for 7 days were phagocytized to a lesser extent than on day 1. Desialylation by neuraminidase induced PS-exposure on PMP, decreased PPL clotting time, and increased PMP phagocytosis. PMP glycans change during platelet storage. Desialylation influences the procoagulant function of PMP and phagocytosis by HepG2 cells.

FLUORESCEIN LABELLED ANNEXIN V STAINING LIMITATIONS FOR DETERMINATION OF BLASTODERMAL CELLS APOPTOSIS

It is known that blastoderm contains not only blastodermal cells (BCs) but also cellular “debris”. These particles include yolk granules and lipid droplets. Some authors used AnnexinV (AnV) staining technique for determination of cell apoptosis. However, AnV is a protein with high affinity to lipids. So the aim of our study was to demonstrate the AnV binding in the blastoderm and yolk cell suspensions. Cell populations were obtained from fertilized chicken eggs. The blastoderms were isolated using filter paper ring method and mechanically fragmented. After that, samples were stained with AnV-FITC and analyzed by fluorescent microscopy (FM) and flow cytometry (FC). FM showed non-specific binding of AnV-FITC on the yolk and lipid particles. Therefore, the FC method using specific nuclear dye DRAQ5 was used to separate BCs from cellular debris. Only 1.82 ± 0.27 % cells were DRAQ5 positive. On the other hand, increase of total events (21 ± 3.30 %) of AnV positive cells without DRAQ5 dye was recorded. Moreover, the affinity of yolk to AnV by FC was also observed (10.45 ± 2.59 %). Significant differences among the groups (P &lt; 0.001) were recorded. This trend was caused by non-specific binding of AnV to the lipid and yolk particles. So it is necessary to stain suspension with nuclear dye to separate BCs than co-stained with some marker of apoptosis. Based on the results we can summarized that AnV staining is inappropriate technique for apoptosis of BCs, however, using nuclear dye we can prevent of non-specific binding.

Участие кахектина и аннексина V в формировании фетоплацентарной недостаточности и инициации преждевременных родов

Objective. To study the role of cachectin and annexin V (AN-V) as a cause for preterm birth against the background of fetoplacental insufficiency formation. Patients and methods. A total of 134 pregnant women without extragenital pathology who gave birth prematurely were examined. The women were divided into three groups: group 1 included 45 women who had early preterm birth (EPB) (between 28–32 weeks and 6 days), group 2 – 42 women who had preterm birth (PB) (between 34-36 weeks and 6 days), and group 3 (control) – 47 women who had full-term pregnancy. Results. Low levels of cachectin (38.95 pg/mL) against high levels of AN-V (0.78 pg/mL) were found among patients with EPB. On the contrary, high levels of both cachectin (77.75 pg/mL) and AN-V (0.75 pg/mL) were observed in PB, indicating an important role of these cellular bioregulators in the labor onset and placentogenesis. Conclusion. The quantitative parameter of cachectin is one of the biochemical markers of preterm birth (between 28–36 weeks and 6 days of gestation) and can be used as an additional prognostic marker of this pathology, and AN-V can serve as a criterion for evaluating placentogenesis. Key words: cachectin, annexin V, preterm birth, fetoplacental

Anticoagulation targeting membrane-bound anionic phospholipids improves outcomes of traumatic brain injury in mice

AbstractSevere traumatic brain injury (TBI) often causes an acute systemic hypercoagulable state that rapidly develops into consumptive coagulopathy. We have recently demonstrated that TBI-induced coagulopathy (TBI-IC) is initiated and disseminated by brain-derived extracellular vesicles (BDEVs) and propagated by extracellular vesicles (EVs) from endothelial cells and platelets. Here, we present results from a study designed to test the hypothesis that anticoagulation targeting anionic phospholipid-expressing EVs prevents TBI-IC and improves the outcomes of mice subjected to severe TBI. We evaluated the effects of a fusion protein (ANV-6L15) for improving the outcomes of TBI in mouse models combined with in vitro experiments. ANV-6L15 combines the phosphatidylserine (PS)-binding annexin V (ANV) with a peptide anticoagulant modified to preferentially target extrinsic coagulation. We found that ANV-6L15 reduced intracranial hematoma by 70.2%, improved neurological function, and reduced death by 56.8% in mice subjected to fluid percussion injury at 1.9 atm. It protected the TBI mice by preventing vascular leakage, tissue edema, and the TBI-induced hypercoagulable state. We further showed that the extrinsic tenase complex was formed on the surfaces of circulating EVs, with the highest level found on BDEVs. The phospholipidomic analysis detected the highest levels of PS on BDEVs, as compared with EVs from endothelial cells and platelets (79.1, 15.2, and 3.5 nM/mg of protein, respectively). These findings demonstrate that TBI-IC results from a trauma-induced hypercoagulable state and may be treated by anticoagulation targeting on the anionic phospholipid-expressing membrane of EVs from the brain and other cells.

VIP152 Is a Novel CDK9 Inhibitor with Efficacy in Chronic Lymphocytic Leukemia

VIP152 Is a Novel CDK9 Inhibitor with Efficacy in Chronic Lymphocytic Leukemia

FLUORESCEIN LABELLED ANNEXIN V STAINING LIMITATIONS FOR DETERMINATION OF BLASTODERMAL CELLS APOPTOSIS

It is known that blastoderm contains not only blastodermal cells (BCs) but also cellular “debris”. These particles include yolk granules and lipid droplets. Some authors used AnnexinV (AnV) staining technique for determination of cell apoptosis. However, AnV is a protein with high affinity to lipids. So the aim of our study was to demonstrate the AnV binding in the blastoderm and yolk cell suspensions. Cell populations were obtained from fertilized chicken eggs. The blastoderms were isolated using filter paper ring method and mechanically fragmented. After that, samples were stained with AnV-FITC and analyzed by fluorescent microscopy (FM) and flow cytometry (FC). FM showed non-specific binding of AnV-FITC on the yolk and lipid particles. Therefore, the FC method using specific nuclear dye DRAQ5 was used to separate BCs from cellular debris. Only 1.82 ± 0.27 % cells were DRAQ5 positive. On the other hand, increase of total events (21 ± 3.30 %) of AnV positive cells without DRAQ5 dye was recorded. Moreover, the affinity of yolk to AnV by FC was also observed (10.45 ± 2.59 %). Significant differences among the groups (P < 0.001) were recorded. This trend was caused by non-specific binding of AnV to the lipid and yolk particles. So it is necessary to stain suspension with nuclear dye to separate BCs than co-stained with some marker of apoptosis. Based on the results we can summarized that AnV staining is inappropriate technique for apoptosis of BCs, however, using nuclear dye we can prevent of non-specific binding.

One year of omega 3 polyunsaturated fatty acid supplementation does not reduce circulating prothrombotic microvesicles in elderly subjects after suffering a myocardial infarction

Circulating microvesicles (cMV) are both effectors and biomarkers of cardiovascular disease (CVD), and the effects of omega 3 polyunsaturated fatty acids (n3 PUFA) in MV shedding are not yet well known. Therefore, we aimed to investigate the effects of long-term n3 PUFA supplementation on cMV release from cells of the vascular compartment in elderly subjects at very high risk of CVD. We included 156 elderly patients 2-8 weeks after suffering an acute myocardial infarction from the OMEMI cohort. Subjects were randomly allocated to receive 930mg EPA+660mg DHA (n3 PUFA intervention) or corn oil (56% linoleic acid, 32% oleic acid, 10% palmitic acid) used as placebo daily for two years. At inclusion and after one-year follow-up, prothrombotic [annexin V (AV)+] cMV derived from blood and vascular cells were phenotyped by flow cytometry. No differences were observed in the levels of cMV between the randomized groups at inclusion in the study. After one-year follow-up, total AV+, platelet-derived CD61+/AV+, and endothelial-derived CD31+/AV+ and CD31+/CD42b-/AV+ cMV increased significantly in both groups. In the n3 PUFA supplemented group, platelet-derived CD62P+/AV+, CD42b+/AV+ and CD31+/CD42b+/AV+; leukocyte-derived CD62L+/AV+, CD45+/AV+, and CD11b+/AV+, as well as endothelial derived CD146+/AV+, CD62E+/AV+, and CD309+/AV+ cMV also increased significantly. No significant differences were however, observed in the changes of cMV levels between groups. In elderly Norwegians who have suffered a recent acute myocardial infarction and treated as per guidelines, long-term supplementation with 1.8g/day n3 PUFA does not modulate prothrombotic MV release from blood and vascular cells. URL: https://www.clinicaltrials.gov; Unique identifier: NCT01841944.

Secretion of Recombinant Human Annexin V in Fusion with the Super Folder GFP for Labelling Phosphatidylserine-Exposing Membranes.

Annexin V (ANXV), mostly characterized by its ability to interact with biological membranes in a calcium-dependent manner. ANXV interacts mainly with phosphatidylserine (PS), for that fluorescent ANXV widely produced and used as a sensitive and specific probe to mark apoptotic cells or any PS-containing bilayers membranes. Many reports described the prokaryotic expression of recombinant human ANXV. To overcome some of E.coli expression limitations, we aimed in this work to investigate unconventional alternative expression system in mammalian cells for producing secreted human ANXV in fusion with the super folder green fluorescent protein (sfGFP). HEK239T cells were transfected using polyethylenimine (PEI) and pcDNA-sfGFP-ANXV plasmid. Forty-eight hours post transfection, direct fluorescence measurement, immunoblotting and ELISA confirmed the presence of secreted sfGFP-ANXV in cells supernatant. The yield of secreted 6 × His-tagged sfGFP-ANXV after affinity purification was estimated to be around 2µg per 1ml of cells supernatant. The secretion system was proper to produce a fully functional sfGFP-ANXV fusion protein in quantities enough to recognize and bind PS-containing surfaces or liposomes. Besides, biological assays such as flow cytometry and fluorescent microscopy confirmed the capacity of the secreted sfGFP-ANXV to detect PS exposure on apoptotic cells. Taken together, we present mammalian expression as a quick, affordable and endotoxin-free system to produce sfGFP-ANXV fusion protein. The secreted sfGFP-ANXV in eukaryotic system is a promising biotechnological tool, it opens up new horizons for additional applications in the detection of PS bearing surfaces and apoptosis invitro andinvivoassays.

Phospholipid Asymmetry in Biological Membranes: Is the Role of Phosphatidylethanolamine Underappreciated?

The asymmetric distribution of phospholipids in cell membranes has been the focus of a lot of important research keeping its biological importance in mind. Most of this research is focused on phosphatidylserine (PS) since it is an apoptotic marker, and there is a robust and easy method available its selective quantification. The aim of this commentary is to argue in favour of another highly abundant membrane lipid, phosphatidylethanolamine (PE) almost always associated with PS. PE has one of the smallest headgroups and shows distinctly asymmetric transbilayer distribution. It is a neutral aminophospholipid and capable of a vastly wider range of interactions as seen in its unique ability to act as a molecular chaperone, implicated role in disease biology and its possible role as an anti-cancer target. There are ample evidences to the fact that PE may also bind to Annexin V (ANV), the PS-specific probe, at higher than 10mol% PE concentrations and absence of Ca2+ ions. An update of the major takeaways from the literature regarding PE asymmetry is also provided.

Cytotoxicity and Oxidative Stress Induction by Root Canal Sealers in Human Periodontal Ligament Fibroblasts: An in vitro Study.

The aim of the study was to investigate the in vitro cytotoxicity, the profile of cell death, and the level of oxidative stress in human periodontal ligament fibroblasts (HPdLFs) after exposure to selected root canal sealers. Freshly mixed or set Endomethasone N (EN), RealSeal (RSEAL), Roeko Seal Automix (RSA), and Sealapex (SP) were incubated with HPdLFs. Fluorescein isothiocyanate (FITC)-annexin V (AnV) and propidium iodide (PI) staining followed by flow cytometry was used to identify the effects of the materials on cell viability and the profile of cell death. 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) with fluorescence-activated cell sorting was used to determine reactive oxygen species (ROS) formation in HPdLFs. Statistical analyses were performed using one-way ANOVA followed by post hoc tests, and significance was determined at P<0.05. All materials reduced the viability of the cultured cells compared with the controls (P<0.05). Fresh SP and EN, and set RSA generated an increase of necrotic cells (P<0.05), whilst fresh RSEAL and RSA induced an elevation of apoptotic cells (P<0.001). Set RSEAL caused a rise in both apoptotic and necrotic cells compared with the controls (P<0.05). Fresh EN, RSEAL, and SP resulted in increased intracellular ROS generation compared with the negative control (P<0.001), whilst fresh RSA and all set materials were ineffective. This in vitro study showed us the materials tested were characterized by differentiated cytotoxic effects on HPdLFs. The fresh and set forms of sealers were capable of eliciting toxic action, inducing apoptosis and/or necrosis in HPdLFs. The toxic effects of fresh EN, RSEAL, and SP might have been due to the induction of oxidative stress in human periodontal fibroblasts. The cytotoxicity of RSA seemed to be related to the involvement of other mechanisms.

Using the SNAP-Tag technology to easily measure and demonstrate apoptotic changes in cancer and blood cells with different dyes.

In vitro and ex vivo development of novel therapeutic agents requires reliable and accurate analyses of the cell conditions they were preclinical tested for, such as apoptosis. The detection of apoptotic cells by annexin V (AV) coupled to fluorophores has often shown limitations in the choice of the dye due to interference with other fluorescent-labeled cell markers. The SNAP-tag technology is an easy, rapid and versatile method for functionalization of proteins and was therefore used for labeling AV with various fluorophores. We generated the fusion protein AV-SNAP and analyzed its capacity for the specific display of apoptotic cells in various assays with therapeutic agents. AV-SNAP showed an efficient coupling reaction with five different fluorescent dyes. Two selected fluorophores were tested with suspension, adherent and peripheral blood cells, treated by heat-shock or apoptosis-inducing therapeutic agents. Flow cytometry analysis of apoptotic cells revealed a strong visualization using AV-SNAP coupled to these two fluorophores exemplary, which was comparable to a commercial AV-Assay-kit. The combination of the apoptosis-specific binding protein AV with the SNAP-tag provides a novel solid method to facilitate protein labeling using several, easy to change, fluorescent dyes at once. It avoids high costs and allows an ordinary exchange of dyes and easier use of other fluorescent-labeled cell markers, which is of high interest for the preclinical testing of therapeutic agents in e.g. cancer research.

Effect of aflatoxin B1 on bovine spermatozoa's proteome and embryo's transcriptome.

This study aims to evaluate the deleterious effect of the mycotoxin aflatoxin B1 (AFB1) on bull spermatozoa and the carryver effect on the developing embryo. Proteomic analysis of AFB1-treated spermatozoa revealed differential expression of proteins associated with biological processes and cellular pathways that involved in spermatozoon function, fertilization competence and embryonic development. Therefore, we assume that factors delivered by the spermatozoa, regardless of DNA fragmentation, are also involved. To confirm this hypothesis, we have used the annexin V (AV) kit to separate the spermatozoa into apoptotic (AV+) and non-apoptotic (AV-) subpopulations which were found to correlate with high- and low DNA fragmentation, respectively. Fertilization with AV+ AFB1-treated spermatozoa, resulted in no blastocyst formation, whereas fertilization with AV- spermatozoa resulted in reduced cleavage rate and formation of genetically altered blastocysts (POU5F1 and SOX2). Microarray analysis of blastocysts derived from 10 µM AFB1-treated spermatozoa revealed differential expression of 345 genes that involved in cellular pathways such as embryo and placenta development, cell cycle, DNA repair and histone modification, and in signaling pathways, especially calcium signaling pathway. This is the first report on deleterious carrying over effects of AFB1 from the bovine spermatozoa to the formed embryo. Our findings suggest that aside from the damage caused by AFB1 to spermatozoa's DNA integrity, additional damage mechanisms are involved.