Soy protein may alleviate osteoarthritis symptoms

Alternative and complementary therapeutic approaches, such as the use of a wide array of herbal, nutritional, and physical manipulations, are becoming popular for relieving symptoms of osteoarthritis (OA). The present study evaluated the efficacy of soy protein (SP) supplementation in relieving the pain and discomfort associated with OA. One hundred and thirty-five free-living individuals (64 men and 71 women) with diagnosed OA or with self-reported chronic knee joint pain not attributed to injury or rheumatoid arthritis were recruited for this double-blind, placebo-controlled, parallel design study. Study participants were assigned randomly to consume 40 g of either supplemental SP or milk-based protein (MP) daily for 3 months. Pain, knee range of motion, and overall physical activity were evaluated prior to the start of treatment and monthly thereafter. Serum levels of glycoprotein 39 (YKL-40), a marker of cartilage degradation, and insulin-like growth factor-I (IGF-I), a growth factor associated with cartilage synthesis, were assessed at baseline and at the end of the study. Overall, SP improved OA-associated symptoms such as range of motion and several factors associated with pain and quality of life in comparison to MP. However, these beneficial effects were mainly due to the effect of SP in men rather than women. Biochemical markers of cartilage metabolism further support the efficacy of SP in men as indicated by a significant increase in serum level of IGF-I and a significant decrease in serum level of YKL-40 compared to MP. This study is the first to provide evidence of possible beneficial effects of SP in the management of OA. Examining and verifying the long-term effects of SP on improving symptoms of OA, particularly in men, is warranted.     

Hispolon induces apoptosis in human gastric cancer cells through a ROS-mediated mitochondrial pathway

Severe side effects and complications such as gastrointestinal and hematological toxicities because of current anticancer drugs are major problems in the clinical management of gastric cancer, which highlights the urgent need for novel effective and less toxic therapeutic approaches. Hispolon, an active polyphenol compound, is known to possess potent antineoplastic and antiviral properties. In this study, we investigated the efficacy of hispolon in human gastric cancer cells and explored the cell death mechanism. Hispolon induced ROS-mediated apoptosis in gastric cancer cells and was more toxic toward gastric cancer cells than toward normal gastric cells, suggesting greater susceptibility of the malignant cells. The mechanism of hispolon-induced apoptosis was that hispolon abrogated the glutathione antioxidant system and caused massive ROS accumulation in gastric cancer cells. Excessive ROS caused oxidative damage to the mitochondrial membranes and impaired the membrane integrity, leading to cytochrome c release, caspase activation, and apoptosis. Furthermore, hispolon potentiated the cytotoxicity of chemotherapeutic agents used in the clinical management of gastric cancer. These results suggest that hispolon could be useful for the treatment of gastric cancer either as a single agent or in combination with other anticancer agents.     

A polysaccharide of the marine alga Capsosiphon fulvescens induces apoptosis in AGS gastric cancer cells via an IGF-IR-mediated PI3K/Akt pathway

Because seaweed extracts have recently been found to have antioxidant and anti-tumor activities, we analyzed a hot-water-soluble polysaccharide (PS) of the marine alga Capsosiphon fulvescens for its potential as a functional foodstuff by determining its effects on cell growth and DNA synthesis. MTS assays showed that the C. fulvescens PS (Cf-PS) significantly inhibited the proliferation of cultured human cancer cells in a dose-dependent manner. Cf-PS-treated AGS cells exhibited a marked increase in caspase-3 activation and a decrease in Bcl-2 expression. In addition, phosphorylation of insulin-like growth factor-I receptor (IGF-IR) was decreased in Cf-PS-treated AGS cells as compared to non-treated control cells, which is consistent with PI3-kinase (PI3K)/Akt activation. Cf-PS also decreased IGF-I-stimulated recruitment of p85 to IGF-IR and IRS-1. These results indicate that Cf-PS inhibits cell proliferation and induces apoptosis by inhibiting IGF-IR signaling and the PI3K/Akt pathway.     

Programmed cell death in the development of the vertebrate inner ear

Programmed cell death is known to be an essential process for accurate ontogeny during the normal development of the inner ear. The inner ear is a complex sensory organ responsible for equilibrium and sound detection in vertebrates. In all vertebrates, the inner ear develops from a single ectodermic patch on the surface of the embryo's head, which undergoes a series of morphological changes to give rise to the complex structure of the adult inner ear. Enlargement and morphogenesis of the inner ear primordium is likely to depend on cellular division, growth, migration, differentiation and apoptosis. Here we describe the regions of programmed cell death that contribute to the final morphological aspect of the adult inner ear. The few studies that focus on the molecules that control this process during inner ear development indicate that the molecules and intracellular signaling pathways activated during the apoptotic response in the inner ear are similar to the previously described for the nervous system. In this review, we will describe some of the growth factors and key pathways that regulate pro- and anti-apoptotic signals and how they cross talk to determine the apoptotic or survival fate of cells in the development of the inner ear.     

Tomentosin induces apoptotic pathway by blocking inflammatory mediators via modulation of cell proteins in AGS gastric cancer cell line

In this study, we investigated the in vitro effect of tomentosin on cell proliferation by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay, reactive oxygen species by 2′,7′‐dichlorofluorescein diacetate staining assay, apoptosis (AO/EtBr, propidium iodide, and 4′,6‐diamidino‐2‐phenylindole staining, mitochondrial membrane potential), cell adherent, cell migration, inflammation, apoptosis, and oxidative stress from gastric cancer cells (GCCs) AGS. Upon their relative cell proliferative, inflammatory, and apoptotic molecular markers were analyzed by using the enzyme‐linked immunosorbent assay and Western blot analysis method. Treatment with tomentosin (IC₅₀ = 20 µM) significantly inhibited cell proliferation and oxidative stress‐induced anti‐cell proliferative (proliferating cell nuclear antigen and cyclin‐D1) also regulated expression, drastically diminished tumor necrosis factor‐α, nuclear factor‐κB, interleukin‐6, and interleukin‐1β expression levels, significantly upregulated Bcl‐2 and Bax expression. Thus, this tomentosin can significantly reduce GCC proliferation via cytotoxicity which is stimulated apoptosis markers via morphology staining changes and inhibitory inflammatory markers. The tomentosin‐induced oxidative stress may be involved to stimulate apoptotic mechanisms via mitochondria‐mediated signaling by the inhibition of inflammation. Taken together, our findings suggest a possible future use of chemotherapeutic agents for pharmacological benefits and as an anti‐cancer treatment option.     

IGF-I binding and receptor signal transduction in primary cell culture of muscle cells of gilthead sea bream: changes throughout in vitro development

We examined the possibility of culturing muscle cells of gilthead sea bream in vitro and assessed variations in insulin-like growth factor-I (IGF-I) binding during myocyte development. The viability of the cell culture was determined by fluorescence-activated cell-sorting analysis, which showed that the percentage of dead cells decreased with cell differentiation. The intracellular reduction of MTT into formazan pigment was preferentially carried out as cells differentiated (from day 4) indicating an increase in metabolic activity. IGF-I-binding assays demonstrated that the number of receptors increased from 190  ±  0.09 fmol/mg protein in myocytes at day 5 to 360 ± 0.09 fmol/mg protein in myotubes at day12. The affinity of IGF-I receptors did not change significantly during cell development (from 0.89 ± 0.09 to 0.98 ± 0.09 nM). The activation of various kinase (ERK 1/2 MAPK and Akt/PKB) proteins by IGFs and insulin was studied by means of Western blot analysis. Levels of MAPK-P increased after IGF and insulin treatment during the first stages of cell culture, with a low response being observed at day 15, whereas IGFs displayed a stimulatory effect on Akt-P throughout the cell culture period, even on day 15. This study thus shows that (1) gilthead sea bream myocytes can be cultured, (2) they express functional IGF-I receptors that increase in number as they differentiate in vitro; (3) IGF signalling transduction through IGF-I receptors stimulates the MAPK and Akt pathways, depending on the development stage of the muscle cell culture. This work was supported by grant AGL2004–06319-C02/ACU from the Ministerio de Educación y Ciencia to I.N. and grant (CRA)-2004 303038/2.2 from the Centre de Referència en Aqüicultura to J.G.     

Insulin-like growth factor-I activation of Akt survival cascade in neuronal cells requires the presence of its cognate receptor in caveolae

Insulin-like growth factor-I (IGF-I) plays important roles in survival of neurons. Caveolae, cholesterol-rich microdomains of plasma membrane, act as platforms for some neurotrophic factors. In this study, we examined a possible role of caveolae in IGF-I signal transduction in pheochromocytoma PC12 cells. IGF-I treatment attenuated serum withdrawal-induced apoptosis, which was reversed by treatment with methyl-beta-cyclodextrin (CD) that removes cholesterol from plasma membrane. Immunocytochemical and subcellular fractionation analyses revealed that IGF-I receptor (IGF-IR) was colocalized with caveolin-1, a major protein component in caveolae, and that CD treatment reduced IGF-IR contents in caveolae. Consistent with these findings, IGF-I phosphorylation of insulin receptor substrate-1 and Akt was impaired, and cholesterol supply restored the IGF-I action. Furthermore, experiments using small interfering RNA revealed that the reduction of caveolin-1 expression impaired the IGF-I action. In addition, the colocalization of IGF-IR with caveolin-1, and the caveolae-dependent IGF-I action were duplicated in primary culture of rat cerebellar granule neurons. These results demonstrate that the presence of IGF-IR in caveolae is required for the neuroprotective action of IGF-I.     

Polygonatum odoratum lectin induces apoptosis and autophagy via targeting EGFR-mediated Ras-Raf-MEK-ERK pathway in human MCF-7 breast cancer cells

Polygonatum odoratum lectin (POL), a mannose-binding GNA-related lectin, has been reported to display remarkable anti-proliferative and apoptosis-inducing activities toward a variety of cancer cells; however, the precise molecular mechanisms by which POL induces cancer cell death are still elusive. In the current study, we found that POL could induce both apoptosis and autophagy in human MCF-7 breast cancer cells. Subsequently, we found that POL induced MCF-7 cell apoptosis via the mitochondrial pathway. Additionally, we also found that POL induces MCF-7 cell apoptosis via EGFR-mediated Ras-Raf-MEK-ERK pathway, suggesting that POL may be a potential EGFR inhibitor. Finally, we used proteomics analyses for exploring more possible POL-induced pathways with EGFR, Ras, Raf, MEK and ERK, some of which were consistent with our in silico network prediction. Taken together, these results demonstrate that POL induces MCF-7 cell apoptosis and autophagy via targeting EGFR-mediated Ras-Raf-MEK-ERK signaling pathway, which would provide a new clue for exploiting POL as a potential anti-neoplastic drug for future cancer therapy.     

Gamma-glutamyltranspeptidase of Helicobacter pylori induces mitochondria-mediated apoptosis in AGS cells

Gamma-glutamyltranspeptidase (GGT) is a novel protein involved in the induction of Helicobacter pylori-mediated apoptosis; however, the signal pathway involved in GGT-induced apoptosis remains unclear. Using DNA recombination techniques, ggt was cloned into pET117b and transformed into Escherichia coli. Recombinant GGT was purified using nickel-affinity resin and was digested by thrombin. Recombinant GGT induced apoptosis in AGS cells in a time-dependent manner, which was confirmed by TUNEL staining, the MTT assay and immunoblot analysis for caspases-9, -3, Bax, Bcl-2, Bcl-xL and cytochrome c release. Activation of caspase-3 and -9 following exposure to GGT increased in a time-dependent manner and upregulation of proapoptotic Bax and a downregulation of antiapoptotic Bcl-2 and Bcl-xL was detected. Apoptotic signals also trigger changes in mitochondria, which lead to a release of cytochrome c into the cytosolic space. The GGT-deficient mutant was not as able to induce apoptosis as the wild-type strain. These results indicate that GGT of H. pylori induces apoptosis via a mitochondria-mediated pathway.     

Forced expression of RNF36 induces cell apoptosis

RNF36 (ring finger protein 36; alias Trif), a member of the RING zinc finger protein family, is expressed in germ cells at round spermatid stages during spermatogenesis. RING finger proteins have been implicated in a variety of functions including oncogenesis, viral replication, and developmental processes. Since no germ cell line is presently available to study the function of RNF36, in this research, we expressed RNF36 truncated and full-length proteins in COS-7 and HEK-293 cell lines to study the effect of RNF36 in somatic cells. The full-length RNF36 protein in both cell lines showed a speckled pattern in the nucleus. Truncated RNF36-1 protein with its putative nuclear localization signal (NLS) remained within the nucleus but lost the speckled pattern. The promyelocytic leukemia (PML) protein, another RING finger protein, was previously identified as present in the nucleus with a speckled pattern. Double-staining and coimmunoprecipitation analyses suggested that RNF36 colocalizes and interacts with PML. In vitro phosphorylation analysis further suggested that RNF36 nuclear localization is under the control of phosphorylation, which might be mediated by p38. Treatment with the p38 inhibitor SB203580 resulted in the cytoplasmic translocation of RNF36. Overexpression of full-length RNF36 in cells induced about half of the transfected cells to undergo cell death. The results of DNA fragmentation assays, flow cytometry assay, and TUNEL staining suggest that the death of RNF36-transfected cells was caused by apoptosis. Following further characterization of the molecular mechanism of RNF36-induced apoptosis, we found that the expression of Bax, caspase-2, and receptor-interacting protein were elevated upon RNF36 induction in test cells. These results suggest that RNF36 may interact with PML and induce cell apoptosis. We suspect that RNF36 may play a role in germ cell homeostasis during spermatogenesis.     

胆红素对慢性阻塞性肺疾病大鼠血小板源性生长因子和胰岛素样生长因子表达的影响

目的探讨胆红素对慢性阻塞性肺疾病（COPD）大鼠肺组织血小板源性生长因子（PDGF-B）和胰岛素样生长因子（IGF-I）表达的影响。方法30只健康清洁级雄性Wistar大鼠（200-250g）,随机分为正常对照组、COPD模型组、胆红素干预组。观察肺组织病理形态,采用免疫组织化学染色检测肺组织中PDGF-B和IGF-I的表达。结果（1）肺病理组织学结果显示胆红素干预组肺病变局限且程度减轻;（2）COPD模型组PDGF-B（1.58±0.72）和IGF-I含量（2.23±0.63）与正常对照组（0.65±0.35,1.34±0.65）比较显著升高（均P〈0.05）;（3）胆红素干预组PDGF-B（1.20±0.56）和IGF-I含量（1.64±0.56）比模型组明显减低（均P〈0.05）,但与正常对照组比较仍较高（均P〈0.05）。结论PDGF-B和IGF-I在COPD显著增加,胆红素可以抑制PDGF-B和IGF-I的表达,可能是其对抗COPD的作用机制之一。     

Role of Akt isoforms in IGF-I-mediated signaling and survival in myoblasts

Oxidative stress has been shown to induce apoptosis in a variety of tissues, while insulin-like growth factor-I (IGF-I) can oppose this effect. We found that H₂O₂ promoted cell death and apoptosis in C2C12 myoblasts, an effect that was completely prevented by exogenous IGF-I. One downstream mediator of IGF-I survival signaling is the serine/threonine kinase Akt, of which three isoforms have been identified in mammals. We found that Akt1 and Akt3 act on pro-apoptotic target molecules in an isoform-specific manner. Both Akt1 and Akt3 were responsible for phosphorylating FoxO3a at S253 and FoxO1 at T24, while Akt1 alone phosphorylated Bad at S136 and FoxO3a at T32. Our results provide evidence for IGF-I-stimulated isoform-specific actions of Akt on molecules involved in promoting apoptosis.     

Escin reduces cell proliferation and induces apoptosis on glioma and lung adenocarcinoma cell lines

Aesculus hippocastanum (the horse chestnut) seed extract has a wide variety of biochemical and pharmacological effects including anti-inflammatory, antianalgesic, and antipyretic activities. The main active compound of this plant is escin. It is known that several medicinal herbs with anti-inflammatory properties have been found to have a role in the prevention and treatment of cancer. In the present study, the cytotoxic effects of escin in the C6 glioma and A549 cell lines were analyzed by MTT. Apoptotic effects of escin on both cell lines were evaluated by Annexin V binding capacity with flow cytometric analysis. Structural and ultrastructural changes were also evaluated using transmission electron microscopy. The results indicated that escin has potent antiproliferative effects against C6 glioma and A549 cells. These effects are both dose and time dependent. Taken together, escin possesses cell cycle arrest on G0/G1 phase and selective apoptotic activity on A549 cells as indicated by increased Annexin V-binding capacity, bax protein expression, caspase-3 activity and morphological changes obtained from micrographs by transmission electron microscopy.     

Down-regulation of protein kinase C activity by sorbitol rapidly induces apoptosis in human gastric cancer cell lines

Although apoptosis-dependent involution of malignant tumors is associated with a number of non-surgical treatments including chemotherapy, most solid tumors, including gastric cancers, respond poorly to these therapies. In the hope of overcoming the resistance mechanism against non-surgical therapies, we studied the apoptosis-resistance mechanism in cells of gastric cancers as a model system. During the course of our study on apoptotic machinery in human gastric cancer cell lines, we previously found a rapid and efficient induction of apoptosis by sorbitol. In the present study, we demonstrated that the down-regulation of PKC activity in response to sorbitol is a major factor in the induction of apoptotic cell death in gastric cancer cells.     

Glycolaldehyde induces apoptosis in a human breast cancer cell line

Activated phagocytes employ myeloperoxidase to generate glycolaldehyde, 2-hydroxypropanal, and acrolein. Because alpha-hydroxy and alpha,beta-unsaturated aldehydes are highly reactive, phagocyte-mediated formation of these products may play a role in killing bacteria and tumor cells. Using breast cancer cells, we demonstrate that glycolaldehyde inactivates glucose-6-phosphate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, and Cu,Zn superoxide dismutase, suppresses cell growth, and induces apoptosis. These results suggest that glycolaldehyde might be an important mediator of neutrophil anti-tumor activity.     

Apigetrin induces extrinsic apoptosis,autophagy and G2/M phase cell cycle arrest through PI3K/AKT/mTOR pathway in AGS human gastric cancer cell

Apigetrin is a flavonoid glycoside phytonutrient derived from fruits and vegetables that is well known for a variety of biological activities such as antioxidant and anti-inflammatory activities. In the current study, we determined the effect of apigetrin on AGS gastric cancer cell. Apigetrin reduced cancer cell proliferation and induced G2/M phase cell cycle arrest by regulating cyclin B1, cdc25c and cdk1 protein expression in AGS cell. Apigetrin treatment caused apoptotic cell death in AGS cells, characterized by the accumulation of apoptosis portion, cleavage of caspase-3 and poly ADP-ribose polymerase (PARP). Apigetrin-treated cells increased the expression of extrinsic apoptosis pathway proteins and mRNA. However, intrinsic apoptosis pathway related proteins were not altered. In addition, AGS cells treated with apigetrin increased autophagic cell death, featured by the formation of autophagic vacuole and acidic vesicular organelles. Autophagy marker proteins, such as LC3B-II and beclin-1, were increased, and p62, an autophagy flux marker protein, was also increased by endoplasmic reticulum stress. Also, the phosphorylation of PI3K/AKT/mTOR pathway proteins and its downstream targets in apigetrin-treated AGS cells was identified to be decreased. Taken together, these data suggest that apigetrin-treated AGS cells induced G2/M phase cell cycle arrest, extrinsic apoptosis and autophagic cell death through PI3K/AKT/mTOR pathway, which can lead to the inhibition of gastric cancer development. Thus, our findings strongly indicate that apigetrin is a basic natural derived compound that could be used as a nutrient source with potential anticancer activities against gastric cancer.     

Endogenous oestrogens and breast cancer risk in premenopausal and postmenopausal women

Breast cancer risk is strongly related to several reproductive and hormonal factors, but the nature of the effects of endogenous oestrogens has been difficult to establish. Data are now available from several large prospective studies with biobanks of stored serum, enabling better characterization of the associations of endogenous oestrogens, and other endogenous hormones, with breast cancer risk. In postmenopausal women, relatively high serum concentrations of oestradiol are associated with a more than twofold increase in the risk for breast cancer, and this probably explains the increase in risk in obese postmenopausal women. In premenopausal women the data available on oestrogens are more limited and difficult to interpret due to the large variations in endogenous oestrogens during the menstrual cycle, but are compatible with a positive association between oestradiol and breast cancer risk. There is also evidence that breast cancer risk is positively associated with androgens, prolactin and insulin-like growth factor-I. Further data are required, with better assays and repeat measures, to provide more accurate estimates of risk and to clarify the role of oestrogens in premenopausal women and the roles of other endogenous hormones.