Polydatin, a natural precursor of resveratrol, induces cell cycle arrest and differentiation of human colorectal Caco-2 cell.

BACKGROUND: Human colon adenocarcinoma cells are resistant to chemotherapeutic agents, such as anthracyclines, that induce death by increasing the reactive oxygen species. A number of studies have been focused on chemo-preventive use of resveratrol as antioxidant against cardiovascular diseases, aging and cancer. While resveratrol cytotoxic action was due to its pro-oxidant properties. In this study, we investigate whether the Resveratrol (trans-3,5,49-trihydroxystilbene) and its natural precursor Polydatin (resveratrol-3-O-b-mono-D-glucoside, the glycoside form of resveratrol) combination, might have a cooperative antitumor effect on either growing or differentiated human adenocarcinoma colon cancer cells. METHODS: The polydatin and resveratrol pharmacological interaction was evaluated in vitro on growing and differentiated Caco-2 cell lines by median drug effect analysis calculating a combination index with CalcuSyn software. We have selected a synergistic combination and we have evaluated its effect on the biological and molecular mechanisms of cell death. RESULTS: Simultaneous exposure to polydatin and resveratrol produced synergistic antiproliferative effects compared with single compound treatment. We demonstrated that polydatin alone or in combination with resveratrol at 3:1 molar ratio synergistically modulated oxidative stress, cell cycle, differentiation and apoptosis. Worthy of note treatment with polydatin induced a nuclear localization and decreased expression of heat shock protein 27, and vimentin redistributed within the cell. CONCLUSIONS: From morphological, and biochemical outcome we obtained evidences that polydatin induced a transition from a proliferative morphology to cell-specific differentiated structures and caused human CaCo-2 cell death by induction of apoptosis. Our data suggest the potential use of polydatin in combination chemotherapy for human colon cancer.

Antiapoptotic seminal vesicle protein IV induces histamine release from human FcepsilonRI+ cells.

BACKGROUND: Seminal vesicle protein number 4 (SV-IV) is a small, basic, multifunctional, intrinsically disordered secretory protein synthesized in large amounts by rat seminal vesicle epithelium under androgen transcriptional control. SV-IV-immunorelated proteins occur in other rat tissues and in humans. METHODS: The in vitro effect of SV-IV on human FcepsilonRI+ cells was investigated by standard immunologic, biochemical and molecular biology procedures. RESULTS: SV-IV-induced histamine release from human basophils and lung mast cells without any influence on leukotriene C(4) release and cell migration. The histamine release rate was slower compared with that induced by anti-IgE, the temperature dependence of the event being similar. SV-IV-induced histamine release was Ca2+-dependent, suggesting a physiological interaction of the protein with FcepsilonRI+ cells. SV-IV and anti-IgE acted synergistically on the histamine release. SV-IV did not induce de novo synthesis of cytokines and growth factors (transforming growth factor-beta(1), interleukin-10, interleukin-13, tumor necrosis factor-alpha, vascular endothelial growth factor A) in FcepsilonRI+ cells. CONCLUSIONS: SV-IV protein induces in human FcepsilonRI+ cells the release of histamine, a proinflammatory, antiapoptotic and immunosuppressive biogenic amine. These data: (1) are consistent with the antiapoptotic and immunosuppressive properties of SV-IV; (2) confirm a regulatory feature of SV-IV on mammal inflammatory reactivity by either inhibiting the arachidonate cascade pathway or stimulating proinflammatory cytokine release from lymphocyte/monocytes and histamine from FcepsilonRI+ cells; (3) raise the possibility of a protective role of SV-IV on implanting hemiallogenic blastocysts against maternal reactive oxygen species and immunological attacks at the uterine implantation site.

In vitro stimulatory effect of anti-apoptotic seminal vesicle protein 4 on purified peroxidase enzymes.

The enzymatic activities of purified horseradish peroxidase, selenium-dependent glutathione peroxidase, thyroid peroxidase and myeloperoxidase, but not that of lactoperoxidase, were markedly enhanced when added into a reaction mixture containing 5 mum native seminal vesicle protein 4, a major protein secreted from rat seminal vesicle epithelium. A further increase of horseradish peroxidase activity was obtained using Ser58-phosphorylated or acetylated seminal vesicle protein 4. The activating effect of native seminal vesicle protein 4 was highest (about 60-fold) on horseradish peroxidase when 4-chloro-1-naphtol was used as the electron donor substrate. The main kinetics parameters of the stimulatory effect on horseradish peroxidase were evaluated and the enzyme-electron donor substrate interaction was investigated by HPLC and electrospray-MS. A native seminal vesicle protein 4/4-chloro-1-naphtol noncovalent adduct was detected when the protein and 4-chloro-1-naphtol were present in the appropriate molar ratio in the horseradish peroxidase-catalyzed reaction. By contrast, no adducts were formed between native seminal vesicle protein 4 and horseradish peroxidase. This native seminal vesicle protein 4/4-chloro-1-naphtol interaction might underlie the native seminal vesicle protein 4-induced horseradish peroxidase stimulation. Furthermore, native seminal vesicle protein 4 was shown by spectrophotometric and electrospray-MS analysis to interact with NADPH, an electron donor substrate of the selenium-dependent glutathione peroxidase/glutathione reductase redox system, with formation of an adduct between them. Although further investigation is required to elucidate the mechanism of adduct formation, this interaction, probably by promoting the release of the NADPH electrons required for glutathione disulphide reduction, could explain the stimulatory effect of seminal vesicle protein 4 on mammalian peroxidases possibly involved in its physiological function on the selenium-dependent glutathione peroxidase/glutathione reductase system. The biological significance of these properties of native seminal vesicle protein 4 might be related to its ability to downregulate reactive oxygen species and oxidative stress-induced apoptosis.

Polydatin administration improves serum biochemical parameters and oxidative stress markers during chronic alcoholism: a pilot study.

AIM: Polydatin, a hydroxystilbene derived from the rhizome of Polygonum cuspidatum, elicits hepatoprotective and neuroprotective effects through its anti-oxidant properties. The present study aimed to determine the effects of oral administration of polydatin in alcoholic patients in order to improve liver biochemical parameters, serum oxidative stress and mental state. We enrolled 20 chronic alcoholic patients hospitalized for rehabilitative therapy. The patients were divided into two groups receiving the following treatment regimes for two weeks: administration of an anti-oxidant nutritional supplement containing glutathione and vitamin C (group 1), or glutathione, vitamin C and polydatin (group 2). RESULTS: The results of the present study show that elevated plasma aspartate aminotransferase and alanine aminotransferase levels in patients after two weeks of alcohol withdrawal were significantly reduced by polydatin (group 2), when compared to group 1. Polydatin also significantly reduced lipid peroxidation levels. Finally, our preliminary data resulting from the analysis of the Mini-Mental Status suggest that polydatin improves cognitive performance. CONCLUSION: Daily dietary administration of polydatin should be considered for prevention and treatment of liver disease and cognitive impairment in alcoholic patients.

Effect of positive charge in VIP 16gamma-glutamyl diamino derivatives on hVPAC1 and hVPAC2 receptor function.

Increase of VPAC receptor s binding to the (16)gamma-glutamyl diaminopropane vasoactive intestinal peptide (VIP-DAP) agonist, a vasoactive intestinal polypeptide (VIP) structural analogue containing a positive charge at position 16, has confirmed the importance of a positive charge at this site. By investigating the effect of distance from the peptide backbone Calpha of a positive charge in position 16, data are reported here concerning: (i) a novel chemical method used for the synthesis of a new family of (16)gamma-glutamyl diamine VIP derivatives differing among them for single carbon atoms and including diaminoethane (VIP-DAE2), diaminopropane (VIP-DAP3), diaminobutane (VIP-DAB4), diaminopentane (VIP-DAP5), and diaminohexane (VIP-DAH6); (ii) functional characterization of these compounds on human VPAC1 and VPAC2 receptors. In more detail, the EC50 and IC50 values, when measured as a function of the alkylic chain length, show in more detail, that the use of VIP-DAB4 derivative changes the IC50 but not the EC50, thus indicating on hVPAC2 receptor an unexpected relationship between binding and activity that differs from that obtained on hVPAC1.

Molecular and cellular determinants of cell-to-cell transmission of HCV in vitro.

It was reported previously that HCV can be transmitted from persistently infected human bone-marrow-derived B-lymphoblastoid cells (TO.FE(HCV)) to human hepatoma cells by cell-to-cell contact. The present study confirms and characterize further such type of HCV infection in vitro. TO.FE(HCV) cells were co-cultured with 2.2.15 hepatoma cells, that are not susceptible to cell-free infection by sera containing HCV of 1b genotype. By this co-cultivation system it was demonstrated that HCV transmission to recipient cells requires de novo virus RNA replication. Several factors may favor HCV-transmission, evidence is provided that TO.FE(HCV) cells were able to select HCV-quasispecies. 5'-UTR and core sequence analysis revealed differences in the HCV-quasispecies composition in serum inoculum and in infected TO.FE B-cells at 4 months post-inoculation. It is considered that the latter may be more successful in replicating HCV in vitro and used to express surface molecules which may be involved in cell-to-cell contact. In TO.FE(HCV) cells replicate distinct, or few close related, HCV-variants correlated with those of serum inoculum. Comparative analysis of tetra-spans and integrins expression undertaken by cytofluorimetry displayed higher level of expression for TO.FE cells in comparison to other human bone-marrow-derived B-cell lines. Overall, the observed persistent in vitro HCV replication is mediated by a continuous cell-to-cell reinfection that may be favored by selection of viral variants and expression of molecules involved in cell adhesion. These observations may provide an explanation for the establishment of HCV infection, the occurrence of chronic infection and HCV-related lymphoproliferative diseases.

The immunomodulatory protein SV-IV protects serum-deprived cells against apoptosis but not against G0/G1 arrest: possible implications for the survival of implanting embryo.

Serum deprivation induced in human lymphoblastoid Raji cells oxidative stress-associated apoptotic death and G0/G1 cell cycle arrest. Addition into culture medium of the immunomodulatory protein Seminal vesicle protein 4 (SV-IV) protected these cells against apoptosis but not against cycle arrest. The antiapoptotic activity was related to: (1) decrease of endocellular reactive Oxygen species (ROS) (2) increase of mRNAs encoding anti-oxidant enzymes (catalase, G6PD) and antiapoptotic proteins (survivin, cox-1, Hsp70, c-Fos); (3) decrease of mRNAs encoding proapoptotic proteins (c-myc, Bax, caspase-3, Apaf-1). The biochemical changes underlaying these effects were probably induced by a protein tyrosine kinase (PTK) activity triggered by the binding of SV-IV to its putative plasma membrane receptors. The ineffectiveness of SV-IV to abrogate the cycle arrest was accounted for by its downregulating effects on D1,3/E G1-cyclins and CdK2/4 gene expression, ppRb/pRb ratio, and intracellular ROS concentration. In conclusion, these experiments: (1) prove that SV-IV acts as a cell survival factor; (2) suggest the involvement of a PTK in SV-IV signaling; (3) point to cell cycle-linked enzyme inhibition as responsible for cycle arrest; (4) provide a model to dissect the cycle arrest and apoptosis induced by serum withdrawal; (5) imply a possible role of SV-IV in the survival of hemiallogenic implanting embryos.