Artificial oocyte activation with Ca2+ ionophore improves reproductive outcomes in patients with fertilization failure and poor embryo development in previous ICSI cycles.

Research question: Does artificial oocyte activation (AOA) by a calcium ionophore (ionomycin) improve the previous fertilization failure or poor embryo development of intracytoplasmic sperm injection (ICSI) account for male factor infertility or other infertility causes? Design: This retrospective study involved 114 patients receiving ICSI-AOA in Shanghai First Maternity and Infant Hospital with previous ICSI fertilization failure or poor embryo development. The previous ICSI cycles of the same patients without AOA served as the control group. The fertilization rates, cleavage rates, transferable embryo rates and blastocyst formation rates of the two groups were compared. Additionally, the clinical pregnancy, implantation rate and live birth rates were also compared to assess the efficiency and safety of AOA. Furthermore, two subgroup analyses were performed in this study based on the cause of infertility and the reason for AOA. The fertilization rate, embryonic development potential and clinical outcome were compared among groups. Results: Among 114 ICSI-AOA cycles, the fertilization rate, top-quality embryo rate, implantation rate, clinical pregnancy per patient and live birth rate per patient were improved significantly compared with previous ICSI cycles (p<0.05 to P< 0.001), and the miscarriage rate in the AOA group was significantly lower than that of the control group (p<0.001). In the AOA subgroups based on the cause of infertility, the fertilization rates of each subgroup were significantly improved compared with previous control cycles except for the mixed factor infertility subgroup (p<0.05 to p<0.001). In the AOA subgroups based on the reason for AOA, the fertilization rates of each subgroup were significantly increased compared with those in their previous ICSI cycle without AOA (p<0.001); however, there was no significant difference in the top-quality embryo rate. No significant improvement was found in the implantation rates and the clinical pregnancy rate in each subgroup except for the poor embryo development subgroup. In the 114 AOA cycles, 35 healthy infants (21 singletons and 7 twins) were delivered without major congenital birth defects or malformations. Conclusion: This study showed that AOA with the calcium ionophore ionomycin can improve the reproductive outcomes of patients with previous fertilization failure and poor embryo development after ICSI.

The effect of pentoxifylline and calcium ionophore treatment on sperm cell biology in oligoasthenoteratozoospermia samples.

The objective of this study was to assess the effects of pentoxifylline (PTX) and Ca2+ ionophore (CI) A12387 treatment on some biological characteristics of sperm cells in oligoasthenoteratozoospermia (OAT) patients. After processing, each sample was divided into four groups: 1, control; 2, exposed to 3.6 mM PTX; 3, exposed to 5 µm calcium ionophore (CI); and 4, exposed to both PTX and CI; 30 min at 37°C. Sperm motility was measured before and after preparation. Acrosome reaction (AR), status of sperm vacuoles, mitochondrial membrane potential (MMP) and DNA fragmentation were assessed using PSA-FITC staining, motile sperm organelle morphology examination (MSOME), JC-1 staining and sperm chromatin dispersion (CSD) test, respectively. Treatment with PTX and CI led to increased and decreased sperm motility, respectively (P < 0.05). Furthermore, vacuole status and rates of sperm DNA fragmentation were not significantly different among groups (P > 0.05). Moreover, the data showed that the rates of AR and disrupted MMP were significantly different between groups (P < 0.05). In conclusion, in vitro application of PTX not only did not have any adverse effects on sperm cell biology characteristics, but also can rectify the harmful effect of CI.

Calcium ionophore improves embryonic development and pregnancy outcomes in patients with previous developmental problems in ICSI cycles.

BACKGROUND: Calcium (Ca2+) ionophores are now mainly considered as efficient treatments for fertilization failure. Recently, its application for rescuing poor embryo development was proposed but still non-routine. This study aimed to explore whether Ca2+ ionophore improves embryo development and pregnancy outcomes in patients with poor embryo development in previous intracytoplasmic sperm injection (ICSI) cycles. METHODS: This study included 97 patients undergoing assisted oocyte activation (AOA) with Ca2+ ionophore (calcimycin, A23187) treatment. Preimplantation embryonic development and clinical outcomes were compared between ICSI-AOA cycles (AOA group) and previous ICSI cycles of the same patients in which poor embryo developmental potential was present (non-AOA group). Subgroups stratified by maternal age (< 35, 35-40, ≥ 40 years, respectively) were analyzed separately. RESULTS: A total of 642 MII oocytes were collected in AOA group, and 689 in non-AOA group. Significantly higher day 3 good quality embryo rate (P = 0.034), good quality blastocyst formation rate (P <  0.001), and utilization rate (P <  0.001) were seen in AOA group. Similar results were seen in each subgroup. For pregnancy outcomes, there were significant differences in clinical pregnancy rate (P = 0.039) and live birth rate (P = 0.045) in total group. In subgroup aged < 35 years, biochemical (P = 0.038), clinical (P = 0.041), and ongoing pregnancy rate (P = 0.037) in AOA group were significantly higher than that in non-AOA group. No significant improvement for clinical outcomes for subgroups aged 35-40 and aged ≥40. CONCLUSION: The study suggests that calcimycin could improve preimplantation development and pregnancy outcomes in patients aged < 35 years with embryo developmental problems in previous ICSI cycles.

Calcium Ionophore A23187 treatment to rescue unfertilized oocytes: a prospective randomized analysis of sibling oocytes.

RESEARCH QUESTION: Can 1-day old human unfertilized oocytes activate and blastulate after exposure to calcium ionophore (Ca.I) A23187? DESIGN: Prospective randomized trial analysis of sibling oocytes. Seventy unfertilized sibling oocytes from 24 couples were randomly split into two groups. In the treatment group, 35 oocytes were cultured with 5-µM Ca.I A23187 for 10 min, washed and cultured until day 6 of development (D+6). The remaining 35 oocytes (control group) were similarly cultured until D+6. Activation, cleavage and blastulation rates were compared between the two groups. RESULTS: Comparable activation rates were observed in the oocytes incubated with Ca.I A23187 and in the control group (11.4% versus 17.1%; P = 0.49). The cleavage rate observed was 45.7% in both groups. None of the embryos reached blastocyst stage. CONCLUSIONS: Activation and cleavage can occur in unfertilized oocytes after the diagnosis of failure to fertilize. Unfortunately, the prevalence of activation is not affected by exposure to Ca.I A23187. Additionally, these embryos have no tangible reproductive potential as they arrest before reaching the blastocyst stage.

The Intercellular Communication Between Mesenchymal Stromal Cells and Hematopoietic Stem Cells Critically Depends on NF-κB Signalling in the Mesenchymal Stromal Cells.

Mesenchymal stromal cells (MSCs) regulate the fate of the hematopoietic stem cells (HSCs) through both cell-cell interactions and paracrine mechanisms involving multiple signalling pathways. We have previously shown that co-culturing of HSCs with CoCl2-treated MSCs expands functional HSCs. While performing these experiments, we had observed that the growth of CoCl2-treated MSCs was significantly stunted. Here, we show that CoCl2-treated MSCs possess activated NF-κB signalling pathway, and its pharmacological inhibition significantly relieves their growth arrest. Most interestingly, we found that pharmacological inhibition of NF-κB pathway in both control and CoCl2-treated MSCs completely blocks their intercellular communication with the co-cultured hematopoietic stem and progenitor cells (HSPCs), resulting in an extremely poor output of hematopoietic cells. Mechanistically, we show that this is due to the down-regulation of adhesion molecules and various HSC-supportive factors in the MSCs. This loss of physical interaction with HSPCs could be partially restored by treating the MSCs with calcium ionophore or calmodulin, suggesting that NF-κB regulates intracellular calcium flux in the MSCs. Importantly, the HSPCs co-cultured with NF-κB-inhibited-MSCs were in a quiescent state, which could be rescued by re-culturing them with untreated MSCs. Our data underscore a critical requirement of NF-κB signalling in the MSCs in intercellular communication between HSCs and MSCs for effective hematopoiesis to occur ex vivo. Our data raises a cautionary note against excessive use of anti-inflammatory drugs targeting NF-κB.

Effect of calcium ionophore (A23187) on embryo development and its safety in PGT cycles.

Background: Intracytoplasmic sperm injection (ICSI) has tremendous advantages for resolving the problem of male infertility. However, ICSI fertilization can fail in some patients because of various reasons, primarily because of the failure of oocyte activation. Oocytes have been activated using calcium ionophore (A23187) in previous clinical cases of ICSI fertilization failure. However, studies on the efficiency of calcium ionophore (A23187) activation, its effects on the developmental potential of embryos, and its effects on pregnancy outcomes after embryo transfer are relatively limited. Methods: In this study, we investigated the safety and long-term efficacy of calcium ionophore (A23187) by analyzing its effects on fertilization, embryonic development, aneuploidy, and pregnancy outcomes in patients undergoing preimplantation genetic testing (PGT) cycles. Results: Comparative analyses of the activation followed by PGT (A-PGT) and PGT groups revealed no significant differences between the oocyte cleavage rate and high-quality embryo rate (98.19% vs. 98.63% and 63.13% vs. 68.39%, respectively, p > 0.05). Although the blastocyst formation rate was significantly lower in the A-PGT group than that in the PGT group (52.22% vs. 59.90%, p < 0.05), no significant difference was observed in the blastocyst aneuploidy rates of the two groups (24.49% vs. 24.55%, p > 0.05). Furthermore, no significant differences were observed between the two groups in terms of the live birth rate (43.75% vs. 52.99%), week of delivery, and birth weight of the infants after transfer of euploid blastocysts (p > 0.05). Furthermore, the 2PN rate, oocyte cleavage rate, blastocyst formation rate, and live birth rate were found to be significantly lower in the A-ICSI group than those in the ICSI group (p < 0.01), but there was no significant difference between the two groups in the week of delivery and birth weight of live births (p > 0.05). Discussion: These results suggest that the use of calcium ionophore (A23187) activation as an option in cases of ICSI fertilization failure does not affect the ploidy of developing blastocysts and has no significant effects on the week of delivery or birth weight after transfer. Thus, we provide a scientific basis for the clinical safety of oocyte activation using calcium ionophore (A23187).

Small Molecule Inhibitors Targeting Nuclear Factor κB Activation Markedly Reduce Expression of Interleukin-2, but Not Interferon-γ, Induced by Phorbol Esters and Calcium Ionophores.

The T-box transcription factor Eomesodermin (Eomes) promotes the expression of interferon-γ (IFN-γ). We recently reported that the small molecule inhibitors, TPCA-1 and IKK-16, which target nuclear factor κB (NF-κB) activation, moderately reduced Eomes-dependent IFN-γ expression in mouse lymphoma BW5147 cells stimulated with phorbol 12-myristate 13-acetate (PMA) and ionomycin (IM). In the present study, we investigated the direct effects of NF-κB on IFN-γ expression in mouse lymphoma EL4 cells and primary effector T cells. Eomes strongly promoted IFN-γ expression and the binding of RelA and NFATc2 to the IFN-γ promoter when EL4 cells were stimulated with PMA and IM. Neither TPCA-1 nor IKK-16 reduced IFN-γ expression; however, they markedly decreased interleukin (IL)-2 expression in Eomes-transfected EL4 cells. Moreover, TPCA-1 markedly inhibited the binding of RelA, but not that of Eomes or NFATc2 to the IFN-γ promoter. In effector CD4+ and CD8+ T cells activated with anti-CD3 and anti-CD28 antibodies, IFN-γ expression induced by PMA and A23187 was not markedly decreased by TPCA-1 or IKK-16 under conditions where IL-2 expression was markedly reduced. Therefore, the present results revealed that NF-κB is dispensable for IFN-γ expression induced by PMA and calcium ionophores in EL4 cells expressing Eomes and primary effector T cells.

Inhibition of Histamine Release from RBL-2H3 Cells by Zoledronate Did Not Affect Rab27a/Doc2a Interaction.

Mast cell (MC) exocytosis is organized by prenylated protein, including Rab families. Among Rab proteins, Rab3a, Rab27a, and Rab11 are responsible for exocytosis arrangement. Rab3a and Rab27a are contributed to exocytosis by interacting with other exocytosis proteins. Zoledronate administration disrupted the Rab prenylation process that affected its interaction with other proteins, and finally, its function. The present study has investigated the effect of zoledronate on the histamine release (HR) from RBL-2H3 cells. The main focus is to answer the question of whether zoledronate affects Rab27a/Doc2a interaction. Histamine release on RBL-2H3 cells after zoledronate or clodronate administration was measured using HPLC-fluorometry. Dinitrophenylated bovine serum albumin (DNP-BSA) (20 ng/mL) or ionomycin (1 µM) are used as secretagogues. Calcium (Ca2+) influx observation was performed using Fura-2A/M. In situ proximity ligation assay (PLA) is used to investigate Rab27a/Doc2a interaction after bisphosphonates (BPs) treatment. Histamine concentration measurement with HPLC-fluorometry showed that zoledronate (30, 100 µM) inhibited HR from antigen-activated RBL-2H3 cells. Zoledronate showed less inhibition in cells activated with ionomycin. Intracellular Ca2+ concentration and Ca2+ flux rate from the extracellular compartment was not changed by zoledronate administration. No changes in Rab27a/Doc2a interaction after zoledronate treatment. Histamine release inhibition by zoledronate in DNP-BSA-activated RBL-2H3 cells is not related to the disruption of Rab27a/Doc2a interaction and is not involve the change in Ca2+ influx.

The protective role of neuronal nitric oxide synthase in endothelial vasodilation in chronic ß-adrenoceptor overstimulation.

AIMS: Nitric oxide synthases (NOSs) are key enzymes regulating vascular function. Previously, we reported that ß-adrenergic (ß-AR) overstimulation, a common feature of cardiovascular diseases, did not impair endothelium-dependent vasodilation, although it resulted in endothelial NOS (eNOS) uncoupling and reduced NO bioavailability. In addition to NO, neuronal NOS (nNOS) produces H2O2, which contributes to vasodilation. However, there is limited information regarding vascular ß-AR signaling and nNOS. In the present study, we assessed the possible role of nNOS-derived H2O2 and caveolins on endothelial vasodilation function following ß-AR overstimulation. MAIN METHODS: Male C57BL/6 wild-type and nNOS knockout mice (nNOS-/-) were treated with the ß-AR agonist isoproterenol (ISO, 15 mg·kg-1·day-1, s.c.) or vehicle (VHE) for seven days. Relaxation responses of aortic rings were evaluated using wire myograph and H2O2 by Amplex Red. KEY FINDINGS: Acetylcholine- or calcium ionophore A23187-induced endothelium-dependent relaxation was similar in aortic rings from VHE and ISO. However, this relaxation was significantly reduced in aortas from ISO compared to VHE when (1) caveolae were disrupted, (2) nNOS was pharmacologically inhibited or genetically suppressed and (3) H2O2 was scavenged. NOS-derived H2O2 production was higher in the aortas of ISO mice than in those of VHE mice. Aortas from ISO-treated mice showed increased expression of caveolin-1, nNOS and catalase, while caveolin-3 expression did not change. SIGNIFICANCE: The results suggest a role of caveolin-1 and the nNOS/H2O2 vasodilatory pathway in endothelium-dependent relaxation following ß-AR overstimulation and reinforce the protective role of nNOS in cardiovascular diseases associated with high adrenergic tone.

Calcium Ionophore (A23187) Rescues the Activation of Unfertilized Oocytes After Intracytoplasmic Sperm Injection and Chromosome Analysis of Blastocyst After Activation.

Calcium is a crucial factor in regulating the biological behavior of cells. The imbalance of calcium homeostasis in cytoplasm will cause abnormal behavior of cells and the occurrence of diseases. In intracytoplasmic sperm injection (ICSI) cycle, the dysfunction of oocyte activation caused by insufficient release of Ca2+ from endoplasmic reticulum is one of the main reasons for repeated fertilization failure. Calcium ionophore (A23187) is a highly selective calcium ionophore, which can form stable complex with Ca2+ and pass through the cell membrane at will, effectively increasing intracellular Ca2+ levels. It has been reported that calcium ionophore (A23187) can activate oocytes and obtain normal embryos. However, there are few studies on unfertilized oocytes after calcium ionophore (A23187) rescue activation in ICSI cycle. The purpose of this study was to analyze the effects of calcium ionophore (A23187) rescue activation on the activation of unfertilized oocytes, embryonic development potential, embryonic development timing and chromosomal aneuploidy, and to compare and analyze the clinical data of patients with calcium ionophore (A23187) activation in clinical application. The results showed that a certain proportion of high-quality blastocysts with normal karyotype could be obtained after calcium ionophore (A23187) rescue activation of unfertilized oocytes, and it did not have a significant effect on the timing of embryo development. In clinical practice, direct activation with calcium ionophore (A23187) after ICSI was better than rescue activation the next day. In conclusions, the studies on the effectiveness and safety of calcium ionophore (A23187) rescue activation for oocytes with ICSI fertilization failure can enable some patients to obtain usable, high-quality embryos during the first ICSI cycle.

Na+-dependent inactivation of vascular Na+/Ca2+ exchanger responsible for reduced peripheral blood flow in neuropathic pain model.

Reduced skin blood flow has been reported in neuropathic pain patients as well as various peripheral neuropathic pain model animals. We have previously shown that vasodilators, which improves reduced skin blood flow, correlatively alleviate neuropathic pain in chronic constriction injury (CCI) mice, a model of neuropathic pain from peripheral nerve injury. Here, we sought to elucidate the mechanism underlying the reduced skin blood flow in CCI rats. The skin blood flow of the ipsilateral plantar arteries was significantly reduced compared to that of the contralateral ones 4 weeks after loose ligation of the sciatic nerve. The contraction induced by noradrenaline, serotonin, and U46619, a thromboxane receptor agonist, in the isolated ipsilateral plantar arteries was significantly enhanced compared to that in the contralateral ones. KB-R7943, a Na+/Ca2+ exchanger (NCX) inhibitor, shifted the concentration-response curves of noradrenaline to the left in the contralateral arteries but had no effect on the ipsilateral side. There was no significant difference in concentration-response curves of noradrenaline between the ipsilateral and contralateral arteries in the presence of KB-R7943. Amiloride, a non-specific inhibitor of Na+ channels and transporters, comparably shifted concentration-response curves of noradrenaline to the left in both the contralateral and ipsilateral arteries. One hundred nM of noradrenaline induced intracellular Ca2+ elevation in the ipsilateral arteries, which was significantly larger than that induced by 300-nM noradrenaline in the contralateral arteries. These results suggest that reduced peripheral blood flow after nerve injury is due to Na+-dependent inactivation of NCX in the ipsilateral plantar arteries.

Binding and antiplatelet activity of quercetin, rutin, diosmetin, and diosmin flavonoids.

Platelets exert an essential role in vascular inflammation and thrombosis. Flavonoids are natural compounds employed for the clinical management of vascular disorders preventing capillary permeability, working as phlebotonics and improving the blood rheology, although their mechanism of action remains partially unknown. The effects of quercetin, rutin, diosmetin and diosmin were investigated in platelet activation utilizing blood from healthy and non-treated volunteers. The arrangement of the different activation states of platelets and GPIIb/IIIa receptor occupation was computed by flow cytometry working with calcium ionophore as pro-aggregant to provoke platelet activation and aggregation. The flavonoids studied demonstrated relevant antiplatelet activity through the blocked of GPIIb/IIIa receptors, the suppression of the platelet activation, as well as the pro-aggregate effect of calcium ionophore. Therefore, whichever of the active ingredients examined could be beneficious in the prevention of cardiovascular disease and this article also contributes to elucidate a new mechanism of action for these drugs.

Calcium signaling mediates a biphasic mechanoadaptive response of endothelial cells to cyclic mechanical stretch.

The vascular system is precisely regulated to adjust blood flow to organismal demand, thereby guaranteeing adequate perfusion under varying physiological conditions. Mechanical forces, such as cyclic circumferential stretch, are among the critical stimuli that dynamically adjust vessel distribution and diameter, but the precise mechanisms of adaptation to changing forces are unclear. We find that endothelial monolayers respond to cyclic stretch by transient remodeling of the vascular endothelial cadherin-based adherens junctions and the associated actomyosin cytoskeleton. Time-resolved proteomic profiling reveals that this remodeling is driven by calcium influx through the mechanosensitive Piezo1 channel, triggering Rho activation to increase actomyosin contraction. As the mechanical stimulus persists, calcium signaling is attenuated through transient down-regulation of Piezo1 protein. At the same time, filamins are phosphorylated to increase monolayer stiffness, allowing mechanoadaptation to restore junctional integrity despite continuing exposure to stretch. Collectively, this study identifies a biphasic response to cyclic stretch, consisting of an initial calcium-driven junctional mechanoresponse, followed by mechanoadaptation facilitated by monolayer stiffening.

Factors affecting intracellular calcium influx in response to calcium ionophore A23187 in equine sperm.

BACKGROUND: Exposure to the calcium ionophore A23187 may present a "universal" sperm treatment for IVF, as it bypasses capacitation pathways. However, success in utilizing A23187 is variable, especially in equine spermatozoa. Notably, albumin is used during A23187 treatment but paradoxically is thought to suppress A23187 action. Essentially no critical data are available on the effects of A23187 and albumin concentrations, ratios, or addition protocols on changes in intracellular calcium ([Ca]i ) in any cell type. OBJECTIVE: To determine factors that affect the action of A23187 on [Ca]i in equine and murine spermatozoa. METHODS: Spermatozoa were loaded with Fluo-4 and changes in fluorescence after A23187 treatment were measured under various conditions using a microplate reader. RESULTS: Concentrations of bovine serum albumin (BSA) and A23187, type of BSA, makeup of A23187 stock solutions (i.e., 1° stock (DMSO) or 2° stock made with medium, water or DMSO), order of addition of spermatozoa and A23187, incubation of media before sperm addition, species of spermatozoa, and time of addition of BSA all affected [Ca]i in response to A23187 treatment. In equine spermatozoa already exposed to 10 µM A23187, addition of BSA to 33 mg/ml to "quench" the A23187 did not affect [Ca]i . When this concentration of BSA was added to spermatozoa exposed to 1 µM A23187, [Ca]i in murine spermatozoa returned to baseline, however, equine spermatozoa continued to exhibit increased [Ca]i . Addition of BSA to 33 mg/ml to media containing 1 µM A23187, prior to addition of spermatozoa, completely inhibited change in [Ca]i in both murine and equine spermatozoa. CONCLUSION: These results represent some of the first critical data on the effects of albumin and other procedural factors on A23187-induced changes in [Ca]i in any cell type. Our findings help to explain the variability in reported response of spermatozoa to A23187 among species and among laboratories.

Early rescue oocyte activation for activation-impaired oocytes with no second polar body extrusion after intracytoplasmic sperm injection.

PURPOSE: When rescue artificial oocyte activation (ROA) is performed on the day after intracytoplasmic sperm injection (ICSI) or later, embryonic development is poor and seldom results in live births. The efficacy of an early ROA after ICSI is unclear. Is early ROA effective in rescuing unfertilized oocytes that have not undergone second polar body extrusion several hours after ICSI? METHODS: We performed retrospective cohort study between October 2016 and September 2019, targeting 2891 oocytes in 843 cycles when ICSI was performed. We performed ROA with calcium ionophore on 395 of the 475 oocytes with no second polar extrusion 2.5-6 h after ICSI. RESULTS: The normal fertilization rate of ROA oocytes was significantly higher than non-ROA oocytes (65.8% vs 6.7%, P < 0.001). The blastocyst development rate in ROA oocytes was significantly lower than spontaneously activated oocytes (48.9% vs 67.2%, P < 0.001). The ROA oocyte implantation rate did not significantly differ from the spontaneously activated oocytes (36.0% vs 41.2%). We observed no differences in the implantation rates and blastocyst development rates over the 2.5-6 h from ICSI until ROA. CONCLUSION: Early ROA is effective, and the optimal timing appears to be 2.5-6 h after ICSI.

Dynamic Changes in the Ability to Release Neutrophil ExtraCellular Traps in the Course of Childhood Acute Leukemias.

Acute leukemias, the most common cancers in children, are characterized by excessive proliferation of malignant progenitor cells. As a consequence of impaired blood cell production, leukemia patients are susceptible to infectious complications-a major cause of non-relapse mortality. Neutrophil extracellular traps (NETs) are involved in various pathologies, from autoimmunity to cancer. Although aberrant NETs formation may be partially responsible for immune defects observed in acute leukemia, still little is known on the NET release in the course of leukemia. Here, we present the first comprehensive evaluation of NETs formation by neutrophils isolated from children with acute leukemia in different stages of the disease and treatment stimulated in vitro with phorbol 12-myristate 13-acetate (PMA), N-formyl-methionyl-leucyl-phenylalanine (fMLP), and calcium ionophore (CI). NETs release was measured using quantitative fluorescent method and visualized microscopically. In this setting, NETs release was significantly impaired in leukemic children both at the diagnosis and during the treatment, and full restoration of neutrophil function was achieved only after successful completion of the leukemia treatment. We suggest that neutrophil function impairment may result from both disease- and treatment-related factors. In this context, deficient innate immune response observed in acute leukemia patients may be present regardless of neutrophil count and contribute to secondary immunodeficiency observed in this population.

Artificial Egg Activation Using Calcium Ionophore.

Artificial oocyte activation, most commonly using calcium ionophore, is a treatment add-on utilized to avoid recurrence of abnormally low or total failed fertilization following in vitro fertilization/intracytoplasmic sperm injection. It aims to modify defective physiological processes, specifically calcium-mediated cell signaling that are critical to events required for fertilization. Routine application of artificial oocyte activation is neither required nor recommended; however, it represents an invaluable intervention for a subgroup of patients affected by sperm-related oocyte activation deficiency.

Formation of mRNP granules in Toxoplasma gondii during the lytic cycle.

Two poly(A) binding proteins (PABPs) of Toxoplasma gondii, were identified and characterized. They were named TgPABPC and TgPABPN as they were found to localize in the cytoplasm and nucleus respectively. TgPABPC, which colocalizes with mRNA granules, is therefore used as a cellular marker of mRNP granules. We detected that the formation of mRNP granules was independent of polymerized microtubules, and that the granules were distributed stochastically within the cytosol. Formation of mRNP granules was found to occur prior to parasite egress when a Ca2+ ionophore is used to induce egress. It was also found that maturation of mRNP granules could be described as a two-phase process. First, prior to host cell lysis, mRNP granules were formed rapidly within the cytosol. Second, the mRNP granule load was reduced within 10 min post egress. To investigate the link between translational state and mRNP granule formation, treatments with salubrinal, nutrient deprivation, and pH stress were used. While salubrinal induced granule formation in tachyzoites, nutrient starvation and pH stress showed no induction effect on mRNP granule formation. Interestingly, salubrinal treatment in bradyzoites did not induce RNP granule formation, thus suggesting that mRNP granule formation is not a ubiquitous response or directly related to translational repression. Instead, mRNP granule formation is likely a response to the rapid increase in non-translating RNA brought on by sudden changes in translational state.

Platelet Apoptotic Response May Be Associated With the Capacity of Aspirin to Inhibit Platelets.

An inadequate platelet response to aspirin (ASA) has been identified in some patients under chronic ASA treatment. The aim of this study was to analyze if ASA-sensitive and ASA-resistant platelets have differences in their apoptotic capability. Clinically stable ischemic coronary patients who had been taking ASA (100 mg/d) for at least 9 months before inclusion were divided into ASA-resistant (n = 11) and ASA-sensitive (n = 13) groups as defined by the PFA-100 test. Platelets from ASA-sensitive patients showed higher expression of the proapoptotic proteins Bak and Bax than those from ASA-resistant patients, although only Bak protein remained different when the results were adjusted by age. In resting platelets, neither caspase-3 activity nor cytosolic cytochrome C levels were different between both experimental groups. Stimulation of platelets with calcium ionophore (10 nmol/L, A23187) increased caspase-3 activity (1.91-fold higher; P < 0.05) and cytosolic cytochrome C levels (1.84-fold higher; P < 0.05) to a higher degree in ASA-sensitive than in ASA-resistant platelets. In conclusion, ASA-sensitive platelets seem to be better prepared to undergo apoptosis during robust platelet activation.

Calcium Ionophore-Induced Extracellular Vesicles Mediate Cytoprotection against Simulated Ischemia/Reperfusion Injury in Cardiomyocyte-Derived Cell Lines by Inducing Heme Oxygenase 1.

Cardioprotection against ischemia/reperfusion injury is still an unmet clinical need. The transient activation of Toll-like receptors (TLRs) has been implicated in cardioprotection, which may be achieved by treatment with blood-derived extracellular vesicles (EVs). However, since the isolation of EVs from blood takes considerable effort, the aim of our study was to establish a cellular model from which cardioprotective EVs can be isolated in a well-reproducible manner. EV release was induced in HEK293 cells with calcium ionophore A23187. EVs were characterized and cytoprotection was assessed in H9c2 and AC16 cell lines. Cardioprotection afforded by EVs and its mechanism were investigated after 16 h simulated ischemia and 2 h reperfusion. The induction of HEK293 cells by calcium ionophore resulted in the release of heterogenous populations of EVs. In H9c2 and AC16 cells, stressEVs induced the downstream signaling of TLR4 and heme oxygenase 1 (HO-1) expression in H9c2 cells. StressEVs decreased necrosis due to simulated ischemia/reperfusion injury in H9c2 and AC16 cells, which was independent of TLR4 induction, but not that of HO-1. Calcium ionophore-induced EVs exert cytoprotection by inducing HO-1 in a TLR4-independent manner.