The acrosome reaction is a prerequisite for fertilization, and its signaling pathway has been investigated for decades. Regardless of the type of inducers present, the acrosome reaction is ultimately mediated by the elevation of cytosolic calcium. Inositol 1,4,5-trisphosphate-gated calcium channels are important components of the acrosome reaction signaling pathway and have been confirmed by several researchers. In this study, we used a novel permeabilization tool BioPORTER^® and first demonstrated its effectiveness in spermatozoa. The inositol 1,4,5-trisphosphate type-1 receptor antibody was introduced into spermatozoa by BioPORTER^® and significantly reduced the calcium influx and acrosome reaction induced by progesterone, solubilized zona pellucida, and the calcium ionophore A23187. This finding indicates that the inositol 1,4,5-trisphosphate type-1 receptor antibody is a valid inositol 1,4,5-trisphosphate receptor inhibitor and provides evidence of inositol 1,4,5-trisphosphate-gated calcium channel involvement in the acrosome reaction in human spermatozoa. Moreover, we demonstrated that the transfer of 1,4,5-trisphosphate into spermatozoa induced acrosome reactions, which provides more reliable evidence for this process. In addition, by treating the spermatozoa with inositol 1,4,5-trisphosphate/BioPORTER^® in the presence or absence of calcium in the culture medium, we showed that the opening of inositol 1,4,5-trisphosphate-gated calcium channels led to extracellular calcium influx. This particular extracellular calcium influx may be the major process of the final step of the acrosome reaction signaling pathway.
Acrosome Reaction/physiology* ; Calcimycin/pharmacology* ; Calcium/pharmacology* ; Calcium Ionophores/pharmacology* ; Drug Delivery Systems ; Humans ; Inositol 1,4,5-Trisphosphate Receptors/metabolism* ; Male ; Progesterone/pharmacology* ; Spermatozoa/metabolism* ; Zona Pellucida/metabolism*

To interact with the egg, the spermatozoon must undergo several biochemical and motility modifications in the female reproductive tract, collectively called capacitation. Only capacitated sperm can undergo acrosomal exocytosis, near or on the egg, a process that allows the sperm to penetrate and fertilize the egg. In the present study, we investigated the involvement of cyclic adenosine monophosphate (cAMP)-dependent processes on acrosomal exocytosis. Inhibition of protein kinase A (PKA) at the end of capacitation induced acrosomal exocytosis. This process is cAMP-dependent; however, the addition of relatively high concentration of the membrane-permeable 8-bromo-cAMP (8Br-cAMP, 0.1 mmol l^-1) analog induced significant inhibition of the acrosomal exocytosis. The induction of acrosomal exocytosis by PKA inhibition was significantly inhibited by an exchange protein directly activated by cAMP (EPAC) ESI09 inhibitor. The EPAC selective substrate activated AE at relatively low concentrations (0.02-0.1 μmol l^-1), whereas higher concentrations (>5 μmol l^-1) were inhibitory to the AE induced by PKA inhibition. Inhibition of PKA revealed about 50% increase in intracellular cAMP levels, conditions under which EPAC can be activated to induce the AE. Induction of AE by activating the actin severing-protein, gelsolin, which causes F-actin dispersion, was inhibited by the EPAC inhibitor. The AE induced by PKA inhibition was mediated by phospholipase C activity but not by the Ca²⁺-channel, CatSper. Thus, inhibition of PKA at the end of the capacitation process induced EPAC/phospholipase C-dependent acrosomal exocytosis. EPAC mediates F-actin depolymerization and/or activation of effectors downstream to F-actin breakdown that lead to acrosomal exocytosis.
8-Bromo Cyclic Adenosine Monophosphate/pharmacology* ; Acrosome/metabolism* ; Acrosome Reaction/drug effects* ; Calcimycin/pharmacology* ; Cyclic AMP/metabolism* ; Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors* ; Exocytosis/drug effects* ; Guanine Nucleotide Exchange Factors/metabolism* ; Humans ; Male ; Protein Kinase Inhibitors/pharmacology* ; Signal Transduction/drug effects* ; Spermatozoa/metabolism* ; Thapsigargin/pharmacology*

OBJECTIVECheongseoikki-tang (CIT, Korean), also called Qingshu Yiqi decoction () and Seisho-ekki-to (Japanese), is well known as an effective traditional combination of herbs for treating cardiovascular diseases. This study was to research its effects on bone marrow-derived mast cell (BMMC)-mediated allergy and inflammation mechanisms.

METHODSIn this study, the biological effect of Cheongseoikki-tang ethanol extract (CITE) was evaluated, focusing on its effects on the production of allergic mediators by phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187 (A23187)-stimulated BMMCs. These allergic mediators included interleukin-6 (IL-6), prostaglandin D2 (PGD2), leukotriene C4 (LTC4), and β-hexosaminidase (β-hex).

RESULTSOur data revealed that CITE inhibited the production of IL-6, PGD2, LTC4, and β-hex induced by PMA plus A23187 (P<0.05).

CONCLUSIONThese findings indicate that CITE has the potential for use in the treatment of allergy.

Animals ; Anti-Inflammatory Agents ; pharmacology ; therapeutic use ; Bone Marrow Cells ; pathology ; Calcimycin ; pharmacology ; Cell Degranulation ; drug effects ; Cell Survival ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Hypersensitivity ; drug therapy ; pathology ; Interleukin-6 ; secretion ; Leukotriene C4 ; pharmacology ; Male ; Mast Cells ; drug effects ; pathology ; physiology ; Mice ; Mice, Inbred BALB C ; Prostaglandin D2 ; biosynthesis ; Tetradecanoylphorbol Acetate ; pharmacology ; beta-N-Acetylhexosaminidases ; metabolism

We studied medium alkalinization in Salvia miltiorrhiza suspension cultures treated with salicylic acid and the effect of Ca2+ in this process through application of calcium channel antagonists (Verapamil, LaCl3, LiCl, 2-APB) and ionophore A23187. The results show that salicylic acid could induce significant medium alkalinization in S. miltiorrhiza culture. Verapamil and LaCl3 or LiCl and 2-APB, two different groups of calcium channel antagonist, significantly inhibited the medium alkalinization induced by salicylic acid. However, the suppression effect of verapamil or LaCl3 on medium alkalinization induced by salicylic acid was higher than that of LiCl or 2-APB. When two types of calcium channel inhibitor (LaCl3 and 2-APB) were used together, the medium alkalinization induced by salicylic acid was completely suppressed and even reduced the pH in medium. On the other hand, A23187 could promote the medium alkalinization. Based on the results above, we speculated that salicylic acid could induce significant medium alkalinization in S. miltiorrhiza culture, depending on the calcium from both extracell and intracell. Moreover, calcium from extracell plays a more dominant role in this process. Reveal of relationship in this research between Ca2+ and medium alkalinization can provide theory evidence for mechanism of the plant secondary metabolism.
Calcimycin ; pharmacology ; Calcium ; chemistry ; Calcium Channel Blockers ; pharmacology ; Calcium Ionophores ; pharmacology ; Cell Culture Techniques ; Culture Media ; chemistry ; Salicylic Acid ; pharmacology ; Salvia miltiorrhiza ; metabolism ; Verapamil ; pharmacology

OBJECTIVETo investigate the effects of endothelial microvesicles (EMVs) induced by calcium ionophore A23187 on H9c2 cardiomyocytes.

METHODSHuman umbilical vein endothelial cells (HUVECs) were treated with 10 micromol/L A23187 for 30 min. EMVs from HUVECs were isolated by ultracentrifugation from the conditioned culture medium. EMVs were characterized using 1 and 2 microm latex beads and anti-PE-CD144 antibody by flow cytometry. For functional research, EMVs at different concentrations were cocultured with H9c2 cardiomyocytes for 6 h. Cell viability of H9c2 cells and the activity of LDH leaked from H9c2 cells were tested by colorimetry. Moreover, apoptosis of H9c2 cells was observed through Hoechst 33258 staining and tested by FITC-Annexin V/PI double staining.

RESULTSEMVs were induced by A23187 on HUVECs, and isolated by ultracentrifugation. We identified the membrane vesicles (< 1 microm) induced by A23187 were CD144 positive. In addition, the EMVs could significantly reduce the viability of H9c2 cells, and increase LDH leakage from H9c2 cells in a dose dependent manner (P < 0.05). Condensed nuclei could be observed with the increasing concentrations of EMVs through Hoechst 33258 staining. Furthermore, increased apoptosis rates of H9c2 cells could be assessed through FITC-Annexin V/PI double staining by flow cytometry.

CONCLUSIONMicrovesicles could be released from HUVECs after induced by A23187 through calcium influx, and these EMVs exerted a pro-apoptotic effect on H9c2 cells by induction of apoptosis.

Annexin A5 ; Apoptosis ; Calcimycin ; pharmacology ; Calcium ; metabolism ; Cell Line ; Cell Membrane ; drug effects ; Coculture Techniques ; Flow Cytometry ; Fluorescein-5-isothiocyanate ; analogs & derivatives ; Human Umbilical Vein Endothelial Cells ; Humans ; Myocytes, Cardiac ; drug effects ; Staining and Labeling

OBJECTIVE: To explore the effect of calcium ionophore (CI) A23187 plus IFN-γ on dendritic cells (DC) from healthy human peripheral blood mononuclear cells (PBMNC). METHODS: PBMNC from healthy donors were treated with GM-CSF plus IL-4, A23187, and A23187 plus IFN-γ, respectively. After culture for 72 h, the change of cellular morphology was observed under light microscope and electron microscope. Surface markers on DC were analyzed by flow cytometry. MTT colorimetry was used to detect the proliferation of allogeneic T cells. Plasma concentrations of IL-12 and IFN-γ were measured by ELISA. RESULTS: PBMNC treated with A23187 plus IFN-γ for 72 h presented DC with typical morphology effectively. The surface markers CD40, CD83, and CD86 were obviously increased in group A23187 plus IFN-γ (P<0.01), but decreased in CD1a (P<0.01). In addition, it evidently stimulated the proliferation of allogeneic T cells. The levels of IL-12 and IFN-γ were significantly increased compared with other groups (P<0.01). CONCLUSION A23187 plus IFN-γ can effectively enhance marked transformation of PBMNC into DC.
Calcimycin ; pharmacology ; Calcium Ionophores ; pharmacology ; Cell Proliferation ; Cells, Cultured ; Dendritic Cells ; drug effects ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Humans ; Interferon-gamma ; metabolism ; pharmacology ; Interleukin-12 ; metabolism ; Interleukin-4 ; pharmacology ; Leukocytes, Mononuclear ; cytology ; T-Lymphocytes ; cytology

BACKGROUNDGlucose regulated protein 78 (GRP78), an endoplasmic reticulum (ER) chaperone, plays a critical role in chemotherapy resistance in a variety of cancers. In this study, we investigated the up-regulation of GRP78 induced by A23187 and its association with the chemotherapeutical sensibility to cisplatin in human lung cancer cell line SPCA1.

METHODSSPCA1 cells were pretreated with A23187 at different concentrations. The expression of GRP78 at the mRNA level was analyzed by RT-PCR; the expression of GRP78 at the protein level was determined by Western blotting and immunofluorescence assay. Cell survival was determined by MTT assay. Cell apoptosis was analyzed by flow cytometry.

RESULTSThe expression of GRP78 at both the mRNA and protein levels was obviously induced by A23187 in SPCA1 cells, with an elevation of GRP78 by 2.1-fold at the mRNA level and by 3.8-fold at the protein level compared to the control. There was a dose-dependent response. Survival curve analysis demonstrated that A23187 induction caused a significant reduction of survival for the cells subjected to cisplatin treatment (P < 0.05). After treatment by cisplatin, the percentage of apoptotic cells in the A23187 pretreated group increased about three fold compared with the control group ((27.53 ± 4.32)% vs. (9.25 ± 3.64)%, P < 0.05).

CONCLUSIONSA23187 treatment was fairly effective for the induction of GRP78 in SPCA1 cells at both the mRNA and protein levels. To a certain extent, GRP78 up-regulation by A23187 was associated with the enhancement of drug sensitivity to cisplatin in human lung cancer cell line SPCA1.

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Blotting, Western ; Calcimycin ; pharmacology ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Flow Cytometry ; Heat-Shock Proteins ; genetics ; metabolism ; Humans ; Lung Neoplasms ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVE: To investigate the relationship between sperm acrosome reaction (AR) and the clinical pregnancy rate of intrauterine insemination (IUI). METHODS: We detected the sperm spontaneous AR rate and Ca2+ ionophore A23187-induced AR rate in 128 patients who accepted IUI treatment, collected their clinical data and analysed the relationship between sperm AR rate and clinical pregnancy rate of IUI. RESULTS: There was no statistical difference between the spontaneous AR rates in the pregnant group and the non-pregnant group (7.7% vs. 7.0%, P>0.05), but there was statistical difference between the induced AR rates(51.9 % vs. 43.5%, P<0.05). There was statistical difference in the clinical pregnancy rate among the 3 IUI groups divided by induced AR rate (≤20.0%, 20.1%-49.9%, and ≥50.0%; 4.8% vs. 12.5% vs. 18.6%, P<0.05). CONCLUSION The spontaneous AR rate has nothing to do with the clinical pregnancy rate of IUI, but the induced AR rate is associated with the clinical pregnancy rate of IUI.
Acrosome Reaction ; drug effects ; physiology ; Adult ; Calcimycin ; pharmacology ; Female ; Humans ; Infertility ; therapy ; Insemination, Artificial, Homologous ; methods ; Male ; Pregnancy ; Pregnancy Rate ; Spermatozoa ; physiology

An abrupt increase of intracellular Ca2+ is observed in cells under hypoxic or oxidatively stressed conditions. The dysregulated increase of cytosolic Ca2+ triggers apoptotic cell death through mitochondrial swelling and activation of Ca2+-dependent enzymes. Transglutaminase 2 (TG2) is a Ca2+-dependent enzyme that catalyzes transamidation reaction producing cross-linked and polyaminated proteins. TG2 activity is known to be involved in the apoptotic process. However, the pro-apoptotic role of TG2 is still controversial. In this study, we investigate the role of TG2 in apoptosis induced by Ca2+-overload. Overexpression of TG2 inhibited the A23187-induced apoptosis through suppression of caspase-3 and -9 activities, cytochrome c release into cytosol, and mitochondria membrane depolarization. Conversely, down-regulation of TG2 caused the increases of cell death, caspase-3 activity and cytochrome c in cytosol in response to Ca2+-overload. Western blot analysis of Bcl-2 family proteins showed that TG2 reduced the expression level of Bax protein. Moreover, overexpression of Bax abrogated the anti-apoptotic effect of TG2, indicating that TG2-mediated suppression of Bax is responsible for inhibiting cell death under Ca2+-overloaded conditions. Our findings revealed a novel anti-apoptotic pathway involving TG2, and suggested the induction of TG2 as a novel strategy for promoting cell survival in diseases such as ischemia and neurodegeneration.
*Apoptosis ; Apoptosis Regulatory Proteins/metabolism ; Calcimycin/pharmacology ; Calcium/*metabolism ; Caspases/metabolism ; Cell Death ; Cell Survival ; Cytochromes c/metabolism ; Down-Regulation ; GTP-Binding Proteins/*metabolism ; HEK293 Cells ; Hela Cells ; Humans ; Ionophores/pharmacology ; Mitochondria/metabolism ; Transglutaminases/*metabolism ; bcl-2-Associated X Protein/genetics/*metabolism

BACKGROUND AND OBJECTIVEThe expression levels of glucose-regulated protein 78 (GRP78) were elevated and correlated with resistance to chemotherapy drug VP-16 in lung cancer cells. However, little is known about the relationship between its expression and resistance to cisplatin in lung cancer cells. The aim of this study was to investigate the expression of GRP78 under the induction of A23187 and its significance in the resistance to anti-tumor drugs cisplatin in a human lung cancer SPCA-1 cell line.

METHODSRT-PCR and Western blot were used to analyze the expression of GRP78 at mRNA and protein levels in SPCA-1 cell line induced byA23187 at different concentrations (0, 1, 2, 4, 6 microM). MTT was used to determine the effect of cisplation on cell survival.

RESULTSThe expressions of GRP78 at both mRNA and protein levels were increased obviously in SPCA-1 cell line induced by A23187, with a manner of dose-dependent of A23187 to a great degree; MTT assay showed that the cell survival rate of the A23187-induced group decreased significantly compare to the control group, also with a concentration-dependent manner of A23187.

CONCLUSIONThe expression of GRP78 at both mRNA and protein levels were increased obviously in SPCA-1 cell line induced by A23187. The enhancement of GRP78 showed a negative correlation with the cell survival rate treated by cisplatin. All these indicated that overexpression of GRP78 can enhance the sensitivity to cisplatin and there is correlation between the expression of GRP78 and resistance to cisplatin of human lung cancer SPCA-1 cell line.

Antineoplastic Agents ; pharmacology ; Blotting, Western ; Calcimycin ; pharmacology ; Cell Line, Tumor ; Cell Survival ; drug effects ; Cisplatin ; pharmacology ; Drug Resistance, Neoplasm ; genetics ; physiology ; Heat-Shock Proteins ; genetics ; metabolism ; Humans ; Reverse Transcriptase Polymerase Chain Reaction