Genistein attenuates LPS-induced inflammatory injury of rat dorsal root ganglion neuron via down-regulating HDAC6 / 中南大学学报(医学版)

OBJECTIVES@#Neuropathic pain (NP) is a chronic pain caused by somatosensory neuropathy or disease, and genistein (Gen) might be a potential drug for the treatment of NP. Therefore, this study aims to investigate the effect of Gen on lipopolysaccharide (LPS)-induced inflammatory injury of dorsal root ganglion neuron (DRGn) in rats and the possible molecular mechanism.@*METHODS@#The DRGn of 1-day-old juvenile rats were taken for isolation and culture. The DRGn in logarithmic growth phase were divided into a control group, a LPS group, a tubastatin hydrochloride (TSA)+LPS group, a Gen1+LPS group, a Gen2+LPS group, a Gen2+LPS+TSA group, a Gen2+pcDNA-histone deacetylase 6 (HDAC6)+LPS group, and a Gen2+pcDNA3.1+LPS group. The LPS group was treated with 1 μg/mL LPS for 24 h; the TSA+LPS group, the Gen1+LPS group, the Gen2+LPS group were treated with 5 μmol/L TSA, 5 μmol/L Gen, 10 μmol/L Gen respectively for 0.5 h, and then added 1 μg/mL LPS for 24 h; the Gen2+TSA+LPS group was treated with 10 μmol/L Gen and 5 μmol/L TSA for 0.5 h and then added 1 μg/mL LPS for 24 h; the Gen2+pcDNA-HDAC6+LPS group and the Gen2+pcDNA3.1+LPS group received 100 nmol/L pcDNA-HDAC6 and pcDNA3.1 plasmids respectively, and 24 h after transfection, 10 μmol/L Gen was pretreated for 0.5 h, and then added 1 μg/mL LPS for 24 h. Real-time RT-PCR was used to detect the HDAC6 mRNA expression in DRGn; CCK-8 method was used to detect cell viability of DRGn; flow cytometry was used to detect cell apoptosis of DRGn; ELISA was used to detect the levels of IL-1β, IL-6, and TNF-α in DRGn culture supernatant; Western blotting was used to detect the protein expression of HDAC6, Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and NF-κB p65 in DRGn.@*RESULTS@#Compared with the control group, the expression levels of HDAC6 mRNA and protein, the expression levels of TLR4 and MyD88 protein in DRGn of LPS group rats were significantly up-regulated, the ratio of p-NF-κB p65/NF-κB p65 was significantly increased, and the activity of DRGn was significantly decreased, the apoptosis rate was significantly increased, and the levels of IL-1β, IL-6 and TNF-α in the DRGn culture supernatant were significantly increased (all P<0.05). Compared with the LPS group, the expression levels of HDAC6 mRNA and protein, TLR4 and MyD88 protein expression levels in DRGn of the TSA+LPS group, the Gen1+LPS group, the Gen2+LPS group and the Gen2+TSA+LPS group were significantly down-regulated, the ratio of p-NF-κB p65/NF-κB p65 was significantly decreased, the activity of DRGn was significantly increased, the apoptosis rate was significantly decreased, and the levels of IL-1β, IL-6 and TNF-α in the DRGn culture supernatant were significantly decreased (all P<0.05), and the above changes were most obvious in the Gen2+TSA+LPS group. Compared with the Gen2+LPS group, the expression levels of HDAC6 mRNA and protein, TLR4 and MyD88 protein expression levels in DRGn of the Gen2+pcDNA-HDAC6+LPS group were significantly up-regulated, the ratio of p-NF-κB p65/NF-κB p65 was significantly increased, the activity of DRGn was significantly decreased, and the apoptosis rate was significantly increased, and the levels of IL-1β, IL-6 and TNF-α in the DRGn culture supernatant were significantly increased (all P<0.05).@*CONCLUSIONS@#Gen can alleviate LPS-induced DRGn inflammatory injury in rats, which might be related to down-regulating the expression of HDAC6 and further inhibiting the activation of TLR4/MyD88/NF-κB signaling pathway.

Biochanin A attenuates myocardial ischemia/reperfusion injury through the TLR4/NF-κB/NLRP3 signaling pathway

Abstract Purpose: Myocardial ischemia/reperfusion (Ml/R) injury is a leading cause of damage in cardiac tissues, with high rates of mortality and disability. Biochanin A (BCA) is a main constituent of Trifolium pratense L. This study was intended to explore the effect of BCA on Ml/R injury and explore the potential mechanism. Methods: In vivo MI/R injury was established by transient coronary ligation in Sprague-Dawley rats. Triphenyltetrazolium chloride staining (TTC) was used to measure myocardial infarct size. ELISA assay was employed to evaluate the levels of myocardial enzyme and inflammatory cytokines. Western blot assay was conducted to detect related protein levels in myocardial tissues. Results: BCA significantly ameliorated myocardial infarction area, reduced the release of myocardial enzyme levels including aspartate transaminase (AST), creatine kinase (CK-MB) and lactic dehydrogenase (LDH). It also decreased the production of inflammatory cytokines (IL-1β, IL-18, IL-6 and TNF-α) in serum of Ml/R rats. Further mechanism studies demonstrated that BCA inhibited inflammatory reaction through blocking TLR4/NF-kB/NLRP3 signaling pathway. Conclusion: The present study is the first evidence demonstrating that BCA attenuated Ml/R injury through suppressing TLR4/NF-kB/NLRP3 signaling pathway-mediated anti-inflammation pathway.

Equol and daidzein decrease migration, invasion and matrix metalloproteinase (MMPs) gene expression in prostate cancer cell lines, DU-145 and PC-3 / Equol y daidzeina disminuyen la migración, invasión y la expresión génica de metaloproteinasa de la matriz(MMPs) en las líneas celulares prostáticas cancerosas DU-145 y PC-3

This search is focused on the study of diet compounds that may have any potential chemopreventive effect against cancer. Some compounds that fulfill this requirement are phytoestrogens. Among them we find genistein (1), the most studied, daidzein (2) and equol (3) (figure 1). To compare the sensitivities of different prostate cancer cells to phytoestrogen treatment, sulphorhodamine B dye assay was performed to determine cell viability. DU-145 and PC-3 prostate cancer cell lines treated with various doses of phytoestrogen (0-12.5-25-50 and 100 μM) for different times (24, 48 and 72h). For cell invasion or migration assay cells were seeded in a Transwell chamber with or without coating Matrigel respectively. DU-145 and PC-3 cells were treated previously with phytoestrogen (50 μM) for 24h. The study showed that equol, daidzein and genistein inhibited migration and invasion in prostate cancer cell lines. Moreover, we analyzed the effects of phytoestrogens in MMP-2 and MMP-9 mRNA expression by RT-PCR. The results indicated that equol, daidzein and genistein diminished the expression of MMP-2 and MMP-9 in a cell-dependent manner. Our data suggested that equol, daidzein and genistein inhibited migration and invasion in prostate cancer cell lines. Moreover, the results also suggest that down-regulation of MMP-2 and MMP- 9 might be involved in the inhibition of invasion of PC-3 and DU-145 cells after genistein, daidzein and equol treatment.

Este trabajo se centra en el estudio de los compuestos de dieta que pueden tener potencial efecto quimiopreventivo contra el cáncer. Algunos de estos compuestos son los fitoestrógenos. Entre ellos encontramos la genisteína (1), el más estudiado, la daidzeína (2) y el equol (3) (figura 1). Para comparar el efecto de estos fitoestrogenos sobre las líneas celulares de cáncer de próstata, DU-145 y PC-3, se utilizó el ensayo de sulforodamina B para determinar la viabilidad celular tras los tratamientos con diferentes concentraciones de fitoestrógenos (0-12.5-25-50-100 μM) durante diferentes tiempos (24, 48, 72 h). Para analizar el efecto sobre la migración celular, las células DU-145 y PC-3 fueron tratadas previamente con una concentración de fitoestrógrno (50 μM) durante 24 horas y sembradas en una cámara Transwell sin recubrir. El estudio mostró que el equol, daidzeína y genisteína inhibió en MMP-2 y MMP-9 expresiones de genes en líneas celulares de cáncer de próstata, la PC-3 y DU-145. Los resultados indicaron que la daidzeína disminuyó la expresión de MMP- 2 y MMP-9 en DU-145 células. Nuestros datos sugieren que equol, daidzeína y genisteína inhiben la migración y la invasión de líneas celulares de cáncer de próstata.

Genistein-induced fluid accumulation in ovariectomised rats' uteri is associated with increased cystic fibrosis transmembrane regulator expression

OBJECTIVE: High genistein doses have been reported to induce fluid accumulation in the uteri of ovariectomised rats, although the mechanism underlying this effect remains unknown. Because genistein binds to the oestrogen receptor and the cystic fibrosis transmembrane regulator mediates uterine fluid secretion, we hypothesised that this genistein effect involves both the oestrogen receptor and cystic fibrosis transmembrane regulator. METHODS: Ovariectomised adult female Sprague-Dawley rats were treated with 25, 50, or 100 mg/kg/day genistein for three consecutive days with and without the ER antagonist ICI 182780. One day after the final drug injection, the animals were humanely sacrificed, and the uteri were removed for histology and cystic fibrosis transmembrane regulator mRNA and protein expression analysis using real-time polymerase chain reaction and Western blotting, respectively. The cystic fibrosis transmembrane regulator protein distribution was analysed visually by immunohistochemistry. RESULTS: The histological analysis revealed an increase in the circumference of the uterine lumen with increasing doses of genistein, which was suggestive of fluid accumulation. Moreover, genistein stimulated a dose-dependent increase in the expression of cystic fibrosis transmembrane regulator protein and mRNA, and high-intensity cystic fibrosis transmembrane regulator immunostaining was observed at the apical membrane of the luminal epithelium following 50 and 100 mg/kg/day genistein treatment. The genistein-induced increase in uterine luminal circumference and cystic fibrosis transmembrane regulator expression was antagonised by treatment with ICI 182780. CONCLUSION: Genistein-induced luminal fluid accumulation in ovariectomised rats' uteri involves the oestrogen receptor and up-regulation of cystic fibrosis transmembrane regulator expression, and these findings reveal the mechanism underlying the effect of this compound on changes in ...

Effects of the phytoestrogen genistein on the development of the reproductive system of Sprague Dawley rats

OBJECTIVES: Genistein is known to influence reproductive system development through its binding affinity for estrogen receptors. The present study aimed to further explore the effect of Genistein on the development of the reproductive system of experimental rats. METHODS: Eighteen post-weaning female Sprague Dawley rats were divided into the following groups: (i) a control group that received vehicle (distilled water and Tween 80); (ii) a group treated with 10 mg/kg body weight (BW) of Genistein (Gen 10); and (iii) a group treated with a higher dose of Genistein (Gen 100). The rats were treated daily for three weeks from postnatal day 22 (P22) to P42. After the animals were sacrificed, blood samples were collected, and the uteri and ovaries were harvested and subjected to light microscopy and immunohistochemical study. RESULTS: A reduction of the mean weekly BW gain and organ weights (uteri and ovaries) were observed in the Gen 10 group compared to the control group; these findings were reversed in the Gen 100 group. Follicle stimulating hormone and estrogen levels were increased in the Gen 10 group and reduced in the Gen 100 group. Luteinizing hormone was reduced in both groups of Genistein-treated animals, and there was a significant difference between the Gen 10 and control groups (p<0.05). These findings were consistent with increased atretic follicular count, a decreased number of corpus luteum and down-regulation of estrogen receptors-a in the uterine tissues of the Genistein-treated animals compared to the control animals. CONCLUSION: Post-weaning exposure to Genistein could affect the development of the reproductive system of ovarian-intact experimental rats because of its action on the hypothalamic-pituitary-gonadal axis by regulating hormones and estrogen receptors.

The Synergistic Apoptotic Interaction of Indole-3-Carbinol and Genistein with TRAIL on Endometrial Cancer Cells

Induction of apoptosis in target cells is a key mechanism by which chemotherapy promotes cell killing. The purpose of this study was to determine whether Indole-3-Carbinol (I3C) and Genistein in combination with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induce apoptosis in endometrial cancer cell (Ishikawa) and to assess apoptotic mechanism. The MTT assay and flow cytometry were performed to determine cell viability and cell cycle. The induction of apoptosis was measured by caspase-3 activity test, DNA fragmentation assay, annexin V binding assay and western blot analysis. There was no effect in cell growth inhibition and cell cycle progression alone or in two-combination. However, the treatment of I3C and Genistein followed by TRAIL showed significant cell death and marked increase in sub-G1 arrest. Three-combination treatment revealed elevated expression of DR4, DR5 and cleaved forms of caspase-3, caspase-8, PARP. The Flip was found down regulated. Moreover, increase in caspase-3 activity and DNA fragmentation indicated the induction of apoptosis. The results indicate that I3C and Genistein with TRAIL synergistically induced apoptosis via death receptor dependent pathway. Our findings might provide a new insight into the development of novel combination therapies against endometrial cancer.

Impact of Lysophosphatidylcholine on the Plasminogen Activator System in Cultured Vascular Smooth Muscle Cells

The balance between tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) regulates fibrinolysis. PAI-1 expression increases in atherosclerotic arteries and vascular smooth muscle cells (VSMCs) are one of major constituents of atheroma. We investigated the impact of lysophosphatidylcholine (lysoPC), an active component of oxidized low-density lipoprotein, on the plasminogen activator system of the rat VSMCs. The lysoPC stimulated the protein and gene expressions of PAI-1 but did not affect the protein expression of t-PA. Fibrin overlay zymography revealed that lysoPC increased the activity of PAI-1 in the conditioned media, while concurrently decreasing that of free t-PA. Vitamin E inhibited the lysoPC-induced PAI-1 expression. Further, lysoPC increased the intracellular reactive oxygen species (ROS) formation. Caffeic acid phenethyl ester, an inhibitor of NF-kappaB, blocked this lysoPC effect. Indeed, lysoPC induced the NF-kappaB-mediated transcriptional activity as measured by luciferase reporter assay. In addition, genistein, an inhibitor of protein-tyrosine kinase (PTK), diminished the lysoPC effect, while 7,12-dimethylbenz[a]anthracene, a stimulator of PTK, stimulated PAI-1 production. In conclusion, lysoPC does not affect t-PA expression but induces PAI-1 expression in the VSMC by mediating NF-kappaB and the genistein-sensitive PTK signaling pathways via oxidative stress. Importantly, lysoPC stimulates the enzyme activity of PAI-1 and suppresses that of t-PA.

A high concentration of genistein down-regulates activin A, Smad3 and other TGF-beta pathway genes in human uterine leiomyoma cells

Previously, we found that high doses of genistein show an inhibitory effect on uterine leiomyoma (UtLM) cell proliferation. In this study, using microarray analysis and Ingenuity Pathways Analysis(TM), we identified genes (up- or down-regulated, > or = 1.5 fold, P < or = 0.001), functions and signaling pathways that were altered following treatment with an inhibitory concentration of genistein (50 microg/ml) in UtLM cells. Downregulation of TGF-beta signaling pathway genes, activin A, activin B, Smad3, TGF-beta2 and genes related to cell cycle regulation, with the exception of the upregulation of the CDK inhibitor P15, were identified and validated by real-time RT-PCR studies. Western blot analysis further demonstrated decreased protein expression of activin A and Smad3 in genistein-treated UtLM cells. Moreover, we found that activin A stimulated the growth of UtLM cells, and the inhibitory effect of genistein was partially abrogated in the presence of activin A. Overexpression of activin A and Smad3 were found in tissue samples of leiomyoma compared to matched myometrium, supporting the contribution of activin A and Smad3 in promoting the growth of UtLM cells. Taken together, these results suggest that down-regulation of activin A and Smad3, both members of the TGF-beta pathway, may offer a mechanistic explanation for the inhibitory effect of a high-dose of genistein on UtLM cells, and might be potential therapeutic targets for treatment of clinical cases of uterine leiomyomas.

Efeitos das isoflavonas em altas doses sobre o útero da rata / Effects of high-dose isoflavones on rat uterus

OBJETIVO: Avaliar o efeito de altas doses de isoflavonas no útero de ratas adultas castradas. MÉTODOS: Ratas virgens ovariectomizadas (n = 40) foram tratadas por 30 dias consecutivos com veículo (GCtrl) ou genisteína nas concentrações 42 (GES42), 125 (GES125) e 250 (GES250) µg/g de peso corporal ao dia. O extrato de soja e o veículo (propilenoglicol) foram administrados por gavagem. Ao final do experimento, foi realizada dosagem sérica de 17 β-estradiol e progesterona, avaliou-se o peso dos animais e dos úteros e foi feito exame colpocitológico. Fragmentos do terço médio dos cornos uterinos foram fixados em formol a 10 por cento e processados para inclusão em parafina para estudo histológico. Cortes de 5 µm de espessura foram corados pelo HE e destinados a estudo em microscopia de luz. Analisou-se a histomorfologia do endométrio, área endometrial, número e área ocupada pelas glândulas, assim como a concentração de eosinófilos presentes na lâmina própria. Os dados numéricos obtidos foram submetidos à análise de variância complementada pelo teste de Tukey-Kramer (p < 0,05). RESULTADOS: Verificou-se que o peso do útero, as áreas endometrial e glandular e o número de glândulas e de eosinófilos foram maiores nos animais dos grupos GES250 > GES125 do que nos outros grupos (GES250 > GES125 > GES42 = GCtrl; p < 0,05). Os dados morfológicos mostraram proliferação endometrial nos grupos ES125 e ES250, que apresentavam endométrio mais desenvolvido que outros grupos. Em todos os animais do grupo ES250 notou-se a presença de metaplasia escamosa. CONCLUSÃO: A administração de isoflavonas em altas doses promove metaplasia escamosa no endométrio.

OBJECTIVE: To evaluate the effects of high-dose isoflavones on the uterus of castrated adult rats. METHODS: Adult, ovariectomized virgin rats (n = 40) were treated by gavage during 30 consecutive days with vehicle (propylene glycol, group GCtrl) or different doses of genistein: 42 (group GES42), 125 (GES125), or 250 (GES250) µg/g body weight per day. Animals were killed, weighed, vaginal and uterine samples were taken for cytologic evaluation, and serum levels of 17 β-estradiol and progesterone were determined. The middle third of the uterine horns was dissected, fixed in 10 percent formaldehyde and processed for paraffin inclusion; 5-µm thick sections were obtained and stained with HE for further histological study under light microscopy. The endometrial morphology and area, number and area of glands, and number of eosinophils in the lamina propria were analyzed. ANOVA and the Tukey-Kramer test were used for statistical analyses. RESULTS: Uterine weight, endometrial glandular area, and number of glands and eosinophils were all higher in GES250 > G125 than in the other groups (GES250 > GES125 > GES42 = GCtrl; p < 0.05). Morphological data showed signs of endometrial proliferation upon treatment with genistein, especially in animals in GES125 and GES250 compared to other groups. In all animals in GES250, signs of uterine squamous metaplasia were observed. CONCLUSION: A short treatment period with high daily doses of isoflavones can promote endometrial squamous metaplasia in ovariectomized rats.

Efeitos de altas doses de genisteína sobre o epitélio mamário de ratas / Effects of high doses of genistein on mammary gland of female rat

OBJETIVO: avaliar os efeitos de altas doses de genisteína sobre o epitélio mamário de ratas adultas. MÉTODOS: após 28 dias da ooforectomia, cinquenta ratas adultas foram divididas em cinco grupos, a saber: um controle (Ctrl), três que receberam genisteína (GEN) nas doses de 46 mg/kg (GEN46), 125 mg/kg (GEN125) e 250 mg/kg (GEN250), e um que recebeu estrogênios conjugados equinos na dose de 50 µg/kg (ECE). As substâncias foram administradas diariamente durante 30 dias consecutivos por gavagem e na última semana de tratamento foi efetuado exame colpocitológico durante sete dias consecutivos. Após o tratamento, os animais foram anestesiados, amostras de sangue foram retiradas para determinação do estradiol e da progesterona, e o primeiro par de mamas inguinais retirado e processado para análise histomorfométrica. Os dados obtidos foram submetidos à análise de variância complementada pelo teste de Tukey-Kramer (p<0,05). RESULTADOS: nos grupos Ctrl e tratados com as diferentes doses de GEN as mamas apresentaram-se atróficas, no entanto mostraram-se desenvolvidas no grupo ECE, onde se notou a presença de inúmeros ductos e alvéolos mamários contendo material eosinófilo em seu interior. A morfometria mostrou maior área de parênquima mamário no grupo ECE (98.870,1±550,4 µm²* por mm²; p<0,05) comparado aos outros grupos (Ctrl=36.875,6±443,4; GEN46=37.001,7±557,4; GEN125=36.480,8±658,3 e GEN250=37.502,8±669,3). O mesmo ocorreu em relação ao número de alvéolos e ductos mamários no grupo ECE (33,2±6,9* por mm²; p<0,05) em relação aos outros grupos (Ctrl=10,4±2,1, GEN 46=11,2±3,1; GEN 125=11,6±2,1 e GEN 250=12,3±2,3). Os níveis de estradiol mostraram-se aumentados no grupo ECE em relação aos outros grupos (9,4±1,7 pg/mL; p<0,05), sendo que os níveis séricos de progesterona mostraram-se semelhantes em todos os grupos de estudo. CONCLUSÃO: a administração de genisteína em altas doses não apresentou efeito proliferativo no tecido mamário de ratas.

PURPOSE: to evaluate the effects of high doses of genistein on the mammary glands of adult female rats. METHODS: Twenty-eight days after oophorectomy, 50 adult female rats were divided into five groups, as follows: a control group (Ctrl), three rats that received genistein (GEN) at the doses of 46 mg/kg (GEN46;), 125 mg/kg (GEN125) and 250 mg/kg (GEN250); one group received conjugated equine estrogen at the dose of 50 µg/g (ECE50). The substances were administered daily for 30 consecutive days by gavage and in the last week of the period of treatment, colpocytological exams were carried out for seven consecutive days. After treatment, the animals were anesthetized, blood samples were collected for estradiol and progesterone determination and the first pair of inguinal mammary glands was removed and processed for histomorphometric analysis. Collected data were subjected to analysis of variance supplemented by the Tukey-Kramer test (p<0.05). RESULTS: the ctrl group and the ones treated with different doses of GEN showed atrophic mammary glands, whereas the glands were more developed in the ECE group, where numerous mammary ducts and alveoli were observed. Morphometry showed a larger area of mammary parenchyma in the ECE group (98.870.1±550.4 µm²* per mm²; p<0.05) compared with other groups (Ctrl=36.875.6±443.4; GEN46=37.001.7±557.4; GEN125=36.480.8±658.3 and GEN250=37.502.8±669.3). The same occurred in the number of alveoli in the ECE group (33.2±6.9* per mm²; p<0.05) compared to the other groups (Ctrl=10.4±2.1, GEN46=11.2±3.1; GEN125=11.6±2.1 and GEN250=12.3±2.3). The estradiol level was higher in the ECE group compared to the other groups (9.4±1.7 pg/mL; p<0.05), whereas serum levels of progesterone were similar in all groups. CONCLUSION: the administration of genistein at high doses had no trophic effect on the mammary glands of rats.

Antiproliferation and Redifferentiation in Thyroid Cancer Cell Lines by Polyphenol Phytochemicals

Thyroid carcinogenesis is accompanied by loss of thyroid-specific functions and refractory to radioiodine and thyroid stimulating hormone (TSH) suppression therapy. Redifferentiating agents have been shown to inhibit tumor growth and improve the response to conventional therapy. Polyphenol phytochemicals (PPs) in fruits and vegetables have been reported to inhibit cancer initiation, promotion, progression and induce redifferentiation in selected types. In this study we examined PPs induce redifferentiation in thyroid cancer cell lines. We investigated the effects of genistein, resveratrol, quercetin, kaempferol, and resorcinol on the F9 embryonal carcinoma cell differentiation model. The thyroid cancer cell lines, TPC-1, FTC-133, NPA, FRO, and ARO, displayed growth inhibition in response to genistein, resveratrol, quercetin. We further demonstrated that genistein decreased the dedifferention marker CD97 in NPA cells and resveratrol decreased CD97 in FTC-133, NPA, FRO cells and quercetin decreased CD97 in all cell lines. We observed increased expression of differentiation marker NIS in FTC-133 cells in response to genistein, and resveratrol but no change in NPA, FRO, ARO cells. Quercetin increased or induced NIS in FTC-133, NPA, FRO cells. These findings suggest that PPs may provide a useful therapeutic intervention in thyroid cancer redifferentiation therapy.

Apoptotic Effects of Genistein, Biochanin-A and Apigenin on LNCaP and PC-3 Cells by p21 through Transcriptional Inhibition of Polo-like Kinase-1

Natural isoflavones and flavones are important dietary factors for prostate cancer prevention. We investigated the molecular mechanism of these compounds (genistein, biochanin-A and apigenin) in PC-3 (hormone-independent/p53 mutant type) and LNCaP (hormone-dependent/p53 wild type) prostate cancer cells. A cell growth rate and apoptotic activities were analyzed in different concentrations and exposure time to evaluate the antitumor activities of genistein, biochanin-A and apigenin. The real time PCR and Western blot analysis were performed to investigate whether the molecular mechanism of these compounds are involving the p21 and PLK-1 pathway. Apoptosis of prostate cancer cells was associated with p21 up-regulation and PLK-1 suppression. Exposure of genistein, biochanin-A and apigenin on LNCaP and PC-3 prostate cancer cells resulted in same pattern of cell cycle arrest and apoptosis. The inhibition effect for cell proliferation was slightly greater in LNCaP than PC-3 cells. In conclusion, flavonoids treatment induces up-regulation of p21 expression, and p21 inhibits transcription of PLK-1, which promotes apoptosis of cancer cells.

Biological activity of genistein and soy extracts: selective induction of some but not all estrogenic responses in the prepubertal rat uterus / Actividad biológica de Genisteína y extractos de soya: inducción selectiva de algunas pero no todas las respuestas estrogénicas en el útero de la rata prepúber

The existence of multiple kinds of estrogen receptors (ERs), involved in independent groups of responses, allows their dissociation and opens the possibility to selectively induce beneficial responses but not those considered at risk (cell proliferation). Based on the low hormone-dependent cancer mortality in Eastern Asia, attributed to high dietary intake of estrogenic isoflavones, we investigated whether genistein (G) or soybean extracts (S) selectively induce some, but not all estrogenic responses in the rat uterus, comparing its activity to that of estradiol-17 (E2). Prepubertal rats were treated with E2, G, concentrated S (Sc), diluted S (Sd), or vehicle, and uterine responses to estrogen were evaluated. Luminal epithelial and myometrial cell hypertrophy, and luminal epithelial RNA increase, were induced by E2, G or S. Uterine eosinophilia, endometrial edema and proliferation of 4 uterine cell-types were induced by E2 only. Results reveal that G and S induce some responses to estrogen but not others, suggesting their use as agents not displaying carcinogenic risk.

La existencia de múltiples tipos de receptores de estrógeno (ERs), involucrados en el desarrollo de grupos independientes de respuestas a estrógeno, permite su disociación y abre la posibilidad de inducir en forma selectiva respuestas benéficas pero no aquellas consideradas de riesgo (proliferación celular). Basado en la baja mortalidad por cánceres hormono-dependientes en el Este Asiático, atribuidos a una alta ingesta dietaria de isoflavonas estrogénicas, nosotros investigamos si la genisteína (G) o extractos de soja (S) inducen en forma selectiva algunas, pero no todas, las respuestas estrogénicas en el útero de rata, comparando su actividad con la del estradiol-17beta (E2). Ratas prepuberales fueron tratadas con E2, G, S concentrado (Sc), S diluido (Sd) o vehículo, y las respuestas estrogénicas en el útero fueron evaluadas. Las hipertrofias celulares en epitelio luminal y miometrio, y el aumento de ARN en células del epitelio luminal fueron inducidas por E2, G o S. La eosinofilia uterina, el edema en estroma endometrial y la proliferación de 4 tipos celulares uterinos fueron inducidos sólo por E2. Los resultados revelan que G y S inducen algunas respuestas estrogénicas pero no otras, sugiriendo su uso terapéutico como agentes estrogénicos que no presentan riesgo de cáncer.

Genistein activates endothelial nitric oxide synthase in broiler pulmonary arterial endothelial cells by an Akt-dependent mechanism

Deregulation of endothelial nitric oxide synthase (eNOS) plays an important role in the development of multiple cardiovascular diseases. Our recent study demonstrated that genistein supplementation attenuates pulmonary arterial hypertension in broilers by restoration of endothelial function. In this study, we investigated the molecular mechanism by using broiler pulmonary arterial endothelial cells (PAECs). Our results showed that genistein stimulated a rapid phosphorylation of eNOS at Ser(1179) which was associated with activation of eNOS/NO axis. Further study indicated that the activation of eNOS was not mediated through estrogen receptors or tyrosine kinase inhibition, but via a phosphatidylinositol 3-kinase (PI3K)/Akt-dependent signaling pathway, as the eNOS activity and related NO release were largely abolished by pharmacological inhibitors of PI3K or Akt. Thus, our findings revealed a critical function of Akt in mediating genistein-stimulated eNOS activity in PAECs, partially accounting for the beneficial effects of genistein on the development of cardiovascular diseases observed in animal models.

Genistein affects the morphology of pituitary ACTH cells and decreases circulating levels of ACTH and corticosterone in middle-aged male rats

The soybean phytoestrogen, genistein, is increasingly consumed as an alternative therapeutic for age-related diseases, namely cardiovascular conditions, cancer and osteoporosis. However, despite the beneficial effects on health, concern has been raised that this isoflavone also acts as an endocrine-disrupting chemical. The aim of this study was to examine the effects of genistein on immunohistomorphometric features of pituitary adrenocorticotropic cells (ACTH) and blood concentrations of ACTH and corticosterone in orchidectomized middle-aged male rats. Sixteen-month-old Wistar rats were divided into sham-operated (SO), orchidectomized (Orx) and genistein-treated orchidectomized (Orx+G) groups. Genistein (30mg/kg/day) was administered subcutaneously for three weeks, while the control groups received the vehicle alone. ACTH cells were identified by the peroxidase-antiperoxidase (PAP) immunohistochemical procedure. Circulating concentrations of ACTH and corticosterone were measured by immunoassay. Orchidectomy reduced (p<0.05) the cell volume and the relative volume of ACTH cells in comparison to SO rats. Genistein treatment further decreased (p<0.05) these morphometric parameters and reduced (p<0.05) circulating ACTH and corticosterone concentrations by more than 20 percent in comparison to both Orx and SO rats. In conclusión, genistein modulated the immunohistomorphometric features of ACTH cells and decreased blood ACTH and corticosterone levels, which supports evidence that this isoflavone affects the hypothalamic-pituitary-adrenal axis and suppresses glucocorticoid hormone secretion.

Interleukin-1beta promotes the expression of monocyte chemoattractant protein-1 in human aorta smooth muscle cells via multiple signaling pathways

Monocyte chemoattractant protein-1 (MCP1) plays a key role in monocyte/macrophage infiltration to the sub-endothelial space of the blood vessel wall, which is a critical initial step in atherosclerosis. In this study, we examined the intracellular signaling pathway of IL-1beta-induced MCP1 expression using various chemical inhibitors. The pretreatment of a phosphatidylcholine (PC)-specific PLC (PC-PLC) inhibitor (D609), PKC inhibitors, or an NF-kappaB inhibitor completely suppressed the IL-1beta-induced MCP1 expression through blocking NF-kappaB translocation to the nucleus. Pretreatment with inhibitors of tyrosine kinase or PLD partially suppressed MCP1 expression and failed to block nuclear NF-kappaB translocation. These results suggest that IL-1beta induces MCP1 expression through activation of NF-kappaB via the PC-PLC/PKC signaling pathway.

Signaling pathway for 2,3,7,8-tetrachlorodibenzo- p-dioxin-induced TNF-alpha production in differentiated THP-1 human macrophages

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a prototypic halogenated aromatic hydrocarbon (HAH), is known as one of the most potent toxicants. At least a part of its toxic effects appears to be derived from its ability to induce TNF-alpha production. However, the signaling pathway of TCDD that leads to TNF-alpha expression has not been elucidated. In this study, we investigated the signaling mechanism of TCDD-induced TNF-alpha expression in PMA-differentiated THP-1 macrophages. TCDD induced both mRNA and protein expression of TNF-alpha in a dose- and time-dependent manner. Alpha-Naphthoflavone (NF), an aryl hydrocarbon receptor (AhR) inhibitor, prevented the TCDD-induced expression of TNF-alpha at both mRNA and protein levels. Genistein, a protein tyrosine kinase (PTK) inhibitor, and PD153035, an EGFR inhibitor, also blocked the increase of TNF-alpha expression by TCDD, indicating the role of EGFR in TCDD-induced TNF-alpha expression. On the other hand, PP2, a c-Src specific inhibitor, did not affect TCDD-induced TNF-alpha expression. EGFR phosphorylation was detected as early as 5 min after TCDD treatment. TCDD-induced EGFR activation was AhR-dependent since co-treatment with alpha-NF prevented it. ERK was found to be a downstream effector of EGFR activation in the signaling pathway leading to TNF-alpha production after TCDD stimulation. Activation of ERK was observed from 30 min after TCDD treatment. PD98059, an inhibitor of the MEK-ERK pathway, completely prevented the TNF-alpha mRNA and protein expression induced by TCDD, whereas inhibitors of JNK and p38 MAPK had no effect. PD153035, an EGFR inhibitor, as well as alpha-NF significantly reduced ERK phosphorylation, suggesting that ERK activation by TCDD was mediated by both EGFR and AhR. These results indicate that TNF-alpha production by TCDD in differentiated THP-1 macrophages is AhR-dependent and involves activation of EGFR and ERK, but not c-Src, JNK, nor p38 MAPK. A signaling pathway is proposed where TCDD induces sequential activation of AhR, EGFR and ERK, leading to the increased expression of TNF-alpha.

A comparative study on the protective effects of 17beta-estradiol, biochanin A and bisphenol A on mammary gland differentiation and tumorigenesis in rats.

Mammary tissue differentiation and tumorigenesis were studied in female rats following subcutaneous injection at 2, 4 and 6 days after birth with low or high doses of 17beta-estradiol (0.1 or 10 microg; E2), biochanin A (0.1 or 10 mg; BCA) or bisphenol A (0.1 or 10.0 mg; BPA). Half of the rats were killed on day 35 to analyze the terminal end bud (TEB), terminal duct (TD) and alveolar bud (AB) of the mammary tissue. The remaining rats were injected, ip, with a dose of 50 mg/kg of N-nitroso-N-methylurea (MNU) at 7 weeks of age and sacrificed 26 weeks later. The incidence and multiplicity of mammary tumors (MT) decreased among all three different treated groups, dose-dependently. However, the pattern of mammary gland differentiation varied. No significant difference was observed after E2 administration. TEB decreased dose-dependently in BCA treated groups and the number of TD and AB were suppressed significantly in BPA high dose group.

zVAD-fmk, unlike BocD-fmk, does not inhibit caspase-6 acting on 14-3-3/Bad pathway in apoptosis of p815 mastocytoma cells

In a preliminary study, we found that benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone (zVAD- fmk), unlike Boc-aspartyl(OMe)-fluoromethylketone (BocD-fmk), at usual dosage could not prevent genistein-induced apoptosis of p815 mastocytoma cells. This study was undertaken to reveal the mechanism underlying the incapability of zVAD-fmk in preventing this type of apoptosis. We observed that 14-3-3 protein level was reduced in genistein-treated cells and that BocD-fmk but not zVAD-fmk prevented the reduction of 14-3-3 protein level and the release of Bad from 14-3-3. We also demonstrated that truncated Bad to Bcl-xL interaction in genistein- treated cells was prevented by BocD-fmk but not by zVAD-fmk treatment. Our data indicate that BocD- fmk, compared to zVAD-fmk, has a certain preference for inhibiting 14-3-3/Bad signalling pathway. We also elucidated that this differential efficacy of BocD-fmk and zVAD-fmk resulted from the different effect in inhibiting caspase-6 and that co-treatment of zVAD-fmk and caspase-6 specific inhibitor substantially prevented genistein-induced apoptosis. Our data shows that caspase-6 plays a role on Bad/14-3-3 pathway in genistein-induced apoptosis of p815 cells, and that the usual dose of zVAD-fmk, in contrast to BocD-fmk, did not prevent caspase-6 acting on 14-3-3/Bad-mediated event.

Efeitos da fosforilação de proteínas em Leishmania L. amazonensis / Effects of protein phosphorylation in Leshmania L. amazonensis

(...) Com o objetivo de abordar tais vias parasito, estudamos bioquimicamente e citoquimicamente a atividade fosfatase ácida. Parasitos tratados com os três inibidores po 1h e 24h apresetaram atividade fosfatase ácida secretada significativametne dimunuída. com a finalidade de estudar as vias de sinalização do parasito na interação com a célula hospedeira, promastigotas pré-tratados com os antagonistas foram incubados com macrófagos peritoneais. Observamos que estaurosporina 1μM inibiu, de forma significativa, a internalização e a sobrevivência intracelular dos parasitos. Nossos dados sugerem que inibidores de proteína cinases podem exercer efeitos na morfologia, infectividade e proliferação de Leishmania, bloqueando o ciclo celular desses parasitos.