Antioxidant status (CoQ10 and Vit. E levels) and immunohistochemical analysis of soft tissues in periodontal diseases

Reactive oxygen species and antioxidant status in periodontal diseases and periodontal-related pathologies is an item of growing interest. Immunohistochemical approach may be usefully employed in the study of soft tissues affected by periodontal disease, giving valuable information on tissue morphology and vascular proliferation that depends directly on the inflammatory state. In order to study CoQ(10) and vitamin E content in healthy gingiva and in gingivitis a new adaptation to previously published methods for their determination was adopted. During gingivitis tissue displayed a large inflammatory infiltration in the lamina propria and a VEGF positive squamous epithelium. The inflammatory infiltration consisted mainly of lymphocytes, plasma cells and neutrophils. Vitamin E dramatically decreased and CoQ(10) remained unchanged despite the increased amount of cells present in the periodontally affected tissues, indicating that continuous oxidative stress which occurred in these structure affected the antioxidant pattern of the tissue.     

Manipulation of the blue light photoreceptor cryptochrome 2 in tomato affects vegetative development, flowering time, and fruit antioxidant content

Cryptochromes are blue light photoreceptors found in plants, bacteria, and animals. In Arabidopsis, cryptochrome 2 (cry2) is involved primarily in the control of flowering time and in photomorphogenesis under low-fluence light. No data on the function of cry2 are available in plants, apart from Arabidopsis (Arabidopsis thaliana). Expression of the tomato (Solanum lycopersicum) CRY2 gene was altered through a combination of transgenic overexpression and virus-induced gene silencing. Tomato CRY2 overexpressors show phenotypes similar to but distinct from their Arabidopsis counterparts (hypocotyl and internode shortening under both low- and high-fluence blue light), but also several novel ones, including a high-pigment phenotype, resulting in overproduction of anthocyanins and chlorophyll in leaves and of flavonoids and lycopene in fruits. The accumulation of lycopene in fruits is accompanied by the decreased expression of lycopene beta-cyclase genes. CRY2 overexpression causes an unexpected delay in flowering, observed under both short- and long-day conditions, and an increased outgrowth of axillary branches. Virus-induced gene silencing of CRY2 results in a reversion of leaf anthocyanin accumulation, of internode shortening, and of late flowering in CRY2-overexpressing plants, whereas in wild-type plants it causes a minor internode elongation.     

Secretion of Annexin II via activation of insulin receptor and insulin-like growth factor receptor

Annexin II is secreted into the extracellular environment, where, via interactions with specific proteases and extracellular matrix proteins, it participates in plasminogen activation, cell adhesion, and tumor metastasis and invasion. However, mechanisms regulating annexin II transport across the cellular membrane are unknown. In this study, we used coimmunoprecipitation to show that Annexin-II was bound to insulin and insulin-like growth factor-1 (IGF-1) receptors in PC12 cells and NIH-3T3 cells overexpressing insulin (NIH-3T3(IR)) or IGF-1 receptor (NIH-3T3(IGF-1R)). Stimulation of insulin and IGF-1 receptors by insulin caused a temporary dissociation of annexin II from these receptors, which was accompanied by an increased amount of extracellular annexin II detected in the media of PC12, NIH-3T3(IR), and NIH-3T3(IGF-1R) cells but not in that of untransfected NIH-3T3 cells. Activation of a different growth factor receptor, the platelet-derived growth factor receptor, did not produce such results. Tyrphostin AG1024, a tyrosine kinase inhibitor of insulin and IGF-1 receptor, was shown to inhibit annexin II secretion along with reduced receptor phosphorylation. Inhibitors of a few downstream signaling enzymes including phosphatidylinositol 3-kinase, pp60c-Src, and protein kinase C had no effect on insulin-induced annexin II secretion, suggesting a possible direct link between receptor activation and annexin II secretion. Immunocytochemistry revealed that insulin also induced transport of the membrane-bound form of annexin II to the outside layer of the cell membrane and appeared to promote cell aggregation. These results suggest that the insulin receptor and its signaling pathways may participate in molecular mechanisms mediating annexin II secretion.     

Role of the PSII-H subunit in photoprotection: novel aspects of D1 turnover in Synechocystis 6803

Photosystem I-less Synechocystis 6803 mutants carrying modified PsbH proteins, derived from different combinations of wild-type cyanobacterial and maize genes, were constructed. The mutants were analyzed in order to determine the relative importance of the intra- and extramembrane domains of the PsbH subunit in the functioning of photosystem (PS) II, by a combination of biochemical, biophysical, and physiological approaches. The results confirmed and extended previously published data showing that, besides D1, the whole PsbH protein is necessary to determine the correct structure of a QB/herbicide-binding site. The different turnover of the D1 protein and chlorophyll photobleaching displayed by mutant cells in response to photoinhibitory treatment revealed for the first time the actual role of the PsbH subunit in photoprotection. A functional PsbH protein is necessary for (i) rapid degradation of photodamaged D1 molecules, which is essential to avoid further oxidative damage to the PSII core, and (ii) insertion of newly synthesized D1 molecules into the thylakoid membrane. PsbH is thus required for both initiation and completion of the repair cycle of the PSII complex in cyanobacteria.     

Novel synthetic phytochelatin-based capacitive biosensor for heavy metal ion detection

A novel capacitance biosensor based on synthetic phytochelatins for sensitive detection of heavy metals is described. Synthetic phytochelatin (Glu-Cys)(20)Gly (EC20) fused to the maltose binding domain protein was expressed in Escherichia coli and purified for construction of the biosensor. The new biosensor was able to detect Hg(2+), Cd(2+), Pb(2+), Cu(2+) and Zn(2+) ions in concentration range of 100 fM-10 mM, and the order of sensitivity was S(Zn)>S(Cu)>S(Hg)>S(Cd) congruent with S(Pb). The biological sensing element of the sensor could be regenerated using EDTA and the storage stability of the biosensor was 15 days.     

Carrageenan formulation prevents macrophage trafficking from vagina: implications for microbicide development

Considerable evidence suggests that human immunodeficiency virus (HIV)-infected macrophages and/or lymphocytes may mediate sexual transmission of HIV. We and others have previously demonstrated that when vitally stained donor mouse lymphocytes or macrophages are placed in the vaginas of mice, some of the stained cells can later be found in the iliac lymph nodes. The aim of this study was to assess the extent of mononuclear cell trafficking from the vagina and to test the possibility that carrageenan formulation, a sulfated polysaccharide formulation containing 3% PDR98-15 carrageenan (PC-515; FMC Biopolymer, Rockland, ME), a vaginal microbicide, would prevent vaginal transmigration of macrophages. When supravitally stained mouse macrophages and T cells were inoculated into the vagina of recipient mice, discrete numbers of donor cells migrated to the recipient iliac and inguinal lymph nodes and spleen. When recipient mice were preinoculated with the carrageenan formulation, the number of macrophages in lymph nodes and spleen was reduced by >90%. In contrast, a methylcellulose formulation, which is believed to be inactive, did not significantly reduce migration to the lymphoid organs. Our findings suggest that the carrageenan formulation blocks cell trafficking of macrophages from vagina and that blocking does not result from cytotoxicity. Blocking cell trafficking may help to prevent sexual transmission of HIV.     

Short-term hypergravity influences NGF and BDNF expression, and mast cell distribution in the lungs and heart of adult male mice

In this study we investigate the effects of short-term hypergravity on lung and heart neurotrophins and mast cell distribution. Our results showed that brain derived-neurotrophic factor (BDNF) protein and mRNA expression are increased in the lungs of mice exposed to hypergravity while in the heart hypergravity causes a marked reduction in BDNF mRNA expression, and a decrease in BDNF protein. Compared to controls, nerve growth factor (NGF) protein was expressed more in the heart of rotated mice. These observations demonstrate that altered hypergravity can affect, though differentially, the local expression of NGF and BDNF proteins and their mRNAs in the lung and heart and indicates that short-term exposure to hypergravity causes a marked increase in BDNF, but not in NGF in the lungs of adult mice. Moreover, mast cells, which are NGF-producing cells and implicated in cardiac and respiratory activity, increased in number in proximity to blood vessels in the heart and in lung airway epithelium of rotated mice. This study indicates that hypergravity influences cardiovascular and respiratory tissue and suggests a neurotrophin involvement in the reaction to this environmental exposure.