Dynamics of intracellular calcium induced by lactate and glucose in rat pachytene spermatocytes and round spermatids

Glycolytic metabolism in meiotic and post-meiotic spermatogenic cells shows differentiation-related changes. The developmental and physiological significance of these metabolic changes is not known. The aim of the present study was to test the hypothesis that glucose and lactate metabolism can modulate intracellular calcium [Ca2+](i) in spermatogenic cells in an opposing and dynamic manner. Fluorescent probes were used to measure [Ca2+](i) and pH(i), and HPLC was used to measure intracellular adenine nucleotides and mitochondrial sensing of ATP turnover. [Ca2+](i) in pachytene spermatocytes and round spermatids was modulated by changes in lactate and glucose concentrations in the media. The kinetics and magnitude of the [Ca2+](i) changes induced by lactate and glucose were different in meiotic and post-meiotic spermatogenic cells. The presence of glucose in the medium induced a decrease in pH(i) in spermatogenic cells. This glucose-induced pH(i) decrease occurred later than the changes in [Ca2+](i), which were also observed when the pH(i) decrease was inhibited, indicating that the glucose-induced [Ca2+](i) increase was not a consequence of pH(i) changes. Hexose phosphorylation in glycolysis was part of the mechanism by which glucose metabolism induced a [Ca2+](i) increase in spermatogenic cells. The sensitivity of [Ca2+](i) to carbohydrate metabolism was higher in round spermatids than in pachytene spermatocytes. Thus, differentiation-related changes in carbohydrate metabolism in spermatogenic cells determine a dynamic and differential modulation of their [Ca2+](i) by glucose and lactate, two substrates secreted by the Sertoli cells.     

Apoptosis in rabbit embryos produced by fertilization or nuclear transfer with fibroblasts and cumulus cells

In this study, we investigated the development, the cell number of the blastocyst, and apoptosis in rabbit nuclear transfer (NT) embryos derived from adult fibroblasts and cumulus cells as compared with embryos derived from in vivo fertilization and in vitro culture. The developmental rate and the total cell number of the blastocyst were significantly lower in NT embryos than in fertilized embryos (FEs). The type of donor cells did not affect the embryonic developmental rate and the total cell number of blastocysts in NT groups. The present study investigated the onset and the frequency of apoptosis in NT embryos and FEs by using a terminal deoxynucleotidyl transferase-mediated dUTP nick and labeling (TUNEL) assay. The earliest positive TUNEL signals were detected at the eight-cell stage in NT embryos and at the morula stage in FEs. The apoptotic index of the total blastocysts, the inner cell mass and the trophoderm was greatly higher in the NT embryos than in FEs. Moreover, the apoptotic index of the blastocyst from fibroblasts was significantly higher than that of the blastocyst from cumulus cells.     

The protein encoded by cancer/testis gene D40/AF15q14 is localized in spermatocytes, acrosomes of spermatids and ejaculated spermatozoa

We have previously identified and cloned a human gene, D40, that is preferentially expressed in testis among normal organs, while it is widely expressed in various human tumor cell lines and primary tumors derived from different organs. In this report, we have examined the expression and localization of this protein in human testis with an antibody specific to D40 protein. In Western analyses, the anti-D40 antibody recognized a major band with a molecular mass of 300 kDa and a minor band of 250 kDa. These bands were not observed in the testis lysates from patients with Sertoli-cell-only syndrome and with Kleinfelter syndrome, who lack germ cells of the testis, indicating that D40 protein is expressed in the germ cells of normal testis. Immunohistochemical studies have revealed that D40 protein is highly expressed in spermatocytes and in the pre-acrosome of round spermatids. In the acrosome, D40 protein expression is observed not inside but outside the acrosome membrane. This is consistent with the finding that the amino-acid sequence at the amino terminal of the D40 protein lacks a hydrophobic signal peptide that is required for proteins to translocate to the membrane. Expression of D40 protein is observed in the acrosome of ejaculated spermatozoa as well, although the level is low compared with that in the pre-acrosome of spermatids. These results suggest that D40 protein plays important roles in spermatogenesis, especially in the formation and maintenance of the acrosome.     

Growth arrest and induction of apoptosis in high-risk leukemia cells by strawberry components in vitro

Strawberries (Fragaria x ananassa) contain phytochemicals that have anti-inflammatory and anti-cancer activity. We investigated the ability of purified strawberry fractions to induce apoptotic cell death in pre-B acute lymphoblastic leukemia (ALL) lines, including lines derived from patients with high-risk B-ALL carrying the t(4;11)(q21;q23) chromosomal translocation. The isolated strawberry constituents were first screened for their anti-cancer activity using a 24 h fluorescence microplate method for detecting mitochondrial membrane depolarization. Active samples were further investigated for induction of apoptosis after addition of multiple doses to the leukemia cells over a period of 72 h. Quercetin, kaempferol, and ellagic acid induced significant apoptosis in the three cancer cell lines, as measured by loss of nuclear DNA, loss of mitochondrial membrane potential, and activation of caspase-3. Our data show that constituents of strawberries induce apoptosis in high-risk leukemia cells and may have potential in the prevention or treatment of this disease.     

白藜芦醇治疗非小细胞肺癌机制的网络药理学分析及实验验证

目的：采用网络药理学和分子对接技术识别分析白藜芦醇抗非小细胞肺癌（NSCLC）的潜在靶点和作用机制,并结合临床数据以及分子生物学实验进行初步验证。方法：通过Swiss Target Prediction数据库和Target net数据库筛选白藜芦醇靶点,通过数据库Genecards、OMIM、TTD收集NSCLC靶点,利用Venny 2.1.0平台获得药物和疾病靶点的交集;应用Cytoscape 3.7.2软件与String数据库生成靶标蛋白互作网络（PPI）,并进行拓扑分析;利用Metascape数据库对交集靶标进行基因本体（GO）功能富集与京都基因与基因组百科全书（KEGG）通路富集分析,得到交集靶标的基因图谱;利用Autodock Vina 软件对排名前三位的核心靶基因与白藜芦醇进行分子对接验证;通过癌症基因组图谱（TCGA）数据库获得临床病例样本,分析相关靶基因在NSCLC患者（n=1017）和健康人群（n=627）的表达情况;细胞水平采用Western Blot检测不同浓度（30、50 μmol/L）白藜芦醇对人肺腺癌A549细胞SRC、EGFR及PI3K/AKT信号通路蛋白表达的影响。结果：筛选得到的潜在靶点共有40个,经过拓扑分析得到关键靶点8个,其中EGFR、SRC、ESR1等靶点与NSCLC密切相关;白藜芦醇抗NSCLC主要涉及肿瘤蛋白多糖、雌激素信号通路、PI3K/AKT等多条信号通路;分子对接显示,白藜芦醇与关键靶点具有稳定的结合能力;临床样本结果显示,靶基因EGFR、SRC、ESR1、HSP90AA1以及MMP9的表达在NSCLC中上调;TNF、CDC42以及RELA的表达在NSCLC中下调;细胞实验结果表明,白藜芦醇药物干预以剂量依赖的方式抑制了人肺腺癌A549细胞中SRC、EGFR、p-PI3K和p-AKT的蛋白表达。结论：揭示了白藜芦醇在治疗NSCLC的过程中涉及多个作用靶点及多条信号通路,明确了白藜芦醇可通过抑制PI3K/AKT信号通路发挥其抗癌效应。

     

Yellow pigment from gardenia fruit: structural identification and evaluation of cytotoxic activity in HepG2 cells by induction of apoptosis

Food Science and Biotechnology - The preparation process of yellow pigment (YP) from gardenia (Gardenia jasminoides) fruit was investigated, and the main components of YP were characterized by...     

Xanthohumol induces apoptosis in cultured 40-16 human colon cancer cells by activation of the death receptor- and mitochondrial pathway

Xanthohumol (XN) is one of the major prenylflavonoids found in hop cones (Humulus lupulus L.). In this study, we investigated the cell growth inhibitory potential of XN on cultured human colon cancer cells. Cell proliferation was measured by sulforhodamine B staining. Poly(ADP-ribose)polymerase (PARP) cleavage, activation of caspases-3, -7, -8, and -9, and Bcl-2 family protein expression were detected by Western blot analyses. XN significantly reduced proliferation of the HCT 116-derived colon cancer cell line 40--16. Half-maximal inhibitory concentrations decreased from 4.1 microM after 24 h treatment to 3.6 and 2.6 microM after 48 and 72 h incubation, respectively. Treatment with 15 microM XN for 48 h and with 5 microM for 72 h led to the detection of the cleaved 89 kDa fragment of 116 kDa PARP as an indication of apoptosis induction. Concomitantly, we observed activation and cleavage of the effector caspases-3 and -7, induced by activation of the initiator caspases -8 and -9. Expression of anti-apoptotic Bcl-2 was down regulated when the cells were treated with XN for 48--72 h. We conclude that induction of apoptosis by downregulation of Bcl-2 and activation of the caspase cascade may contribute to the chemopreventive or therapeutic potential of XN.     

Induction of apoptosis by tomato using space mutation breeding in human colon cancer SW480 and HT‐29 cells

BACKGROUND: As far as we know, there have been no reports concerning the functional characteristics of tomatoes using space mutation breeding. The aim of this study was to evaluate the anti‐colon cancer effect of tomatoes M1 and M2 using space mutation breeding. RESULTS: In the present study, obvious anti‐cancer activity was shown with tomato juice of M1 and M2 and their parent CK treatment in colon cancer cell lines SW480 and HT‐29 in cell growth inhibition. In addition, SW480 cells were more sensitive to M1 and M2 than HT‐29 cells in cell apoptosis. Furthermore, M1 and M2 induced cell cycle arrest both in G0–G1 and G2/M phases. CONCLUSION: These data suggest that consumption of tomato using space mutation breeding may provide benefits to inhibit growth of colon cancer cells. Therefore, tomato production using space mutation breeding may be a good candidate for development as a dietary supplement in drug therapy for colon cancer. Copyright © 2010 Society of Chemical Industry     

Induction of apoptosis by Myagropsis myagroides extracts is associated with a caspase dependent pathway and reactive oxygen species generation in human cancer cells

The purpose of this study was to elucidate the mechanisms underlying apoptosis induced by an ethanol extracts from Myagropsis myagroides (ME) in HeLa, U937, and PC-3 cells. ME treatment for 24 h significantly inhibited cell viability in a dose-dependent manner, and induced apoptosis. Moreover, ME treatment triggered the cleavage of caspase-8, ?9, ?3, and poly(ADP-ribose) polymerase (PARP). A general caspase inhibitor (z-VAD-fmk) inhibited ME-induced activation of caspase-3, PARP cleavage, and cell death. ME treatment also triggered the release of cytochrome c from the mitochondria to the cytosol and stimulated the cleavage of Bid, up-regulation of Bax, and down-regulation of Bcl-2. Furthermore, ME treatment caused reactive oxygen species (ROS) generation. An antioxidant N-acetylcysteine (NAC) blocked MEinduced activation of caspase-3, PARP cleavage, and cell death. Overall, these results suggest that ME-induced apoptosis is mediated by a caspase dependent pathway and ROS generation in HeLa, U937, and PC-3 cells.     

Involvement of MAPK, Bcl-2 family, cytochrome c, and caspases in induction of apoptosis by 1,6-O,O-diacetylbritannilactone in human leukemia cells

1,6-O,O-diacetylbritannilactone (OODBL) isolated from Inula britannica, exhibits potent antitumor activity against several human cancer cell lines. However, the molecular mechanism of OODBL in the induction of anticancer activity is still unclear. In the present study, we demonstrated that OODBL induced the occurrence of apoptosis in human leukemic (HL-60) cells and cell arrest at the S phase. On the other hand, activation of caspase-8, -9, and -3, phosphorylation of Bcl-2 and Bid, and increased release of cytochrome c from mitochondria into cytosolic fraction were detected in OODBL-treated HL-60 cells. We further demonstrated that production of reactive oxygen species (ROS), activation of mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) signaling pathways may play an important role in OODBL-induced apoptosis. The results from the present study highlight the molecular mechanisms underlying OODBL-induced anticancer activity.     

Induction of the cell cycle arrest and apoptosis by flavonoids isolated from Korean Citrus aurantium L. in non-small-cell lung cancer cells

This study investigated the anti-proliferative and apoptotic effect of flavonoids isolated from Korean Citrus aurantium L. using A549 lung cancer cells. Flavonoids potently inhibited of A549 cells in a dose-dependent manner, whereas flavonoids had a weak inhibitory effect on proliferation of WI-38 cells. Flow cytometry and Western blot analysis showed that flavonoids induced cell cycle arrest at the G2/M checkpoint by controlling the proteins expression level of cyclin B1, cdc2, cdc25c and p21^WAF1/CIP1. Also, flavonoids induced apoptosis through the regulation of the expression of caspases, cleaved PARP and Bax/Bcl-xL ratio. The activity of caspase-3 on A549 cells increased in a dose-dependent manner. These results clearly indicated that the anti-cancer effect of flavonoids on A549 cells follows multiple cellular pathways through G2/M arrest and the induction of apoptosis.     

Neuroprotective effects of N-acetylglucosamine against hydrogen peroxide-induced apoptosis in human neuronal SK-N-SH cells by inhibiting the activation of caspase-3, PARP, and p38

Neuroprotective effects of N-acetylglucosamine (GlcNAc), a monosaccharide derivative of glucose, against H₂O₂-induced neurotoxicity and its underlying mechanism in human SK-N-SH neuroblastoma cells were investigated. Pretreatment of GlcNAc prior to exposure of cells to H₂O₂ stress significantly reduced the H₂O₂-mediated neuronal cell death and apoptosis. The GlcNAc dose-dependently decreased the level of intracellular reactive oxygen species (ROS) in H₂O₂-treated cells and also effectively inhibited H₂O₂-induced apoptotic features such as DNA fragmentation, caspase-3, and poly ADP-ribose polymerase (PARP) cleavages, and p38 phosphorylation. These results suggested that GlcNAc might potentially serve as agents for prevention of neurodegenerative diseases caused by oxidative stresses and this effect may be associated with the suppression of caspase-3, PARP, and p38 activation.