The balance between matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) is a key determinant in the homeostasis of the extracellular matrix. We have identified two cis-acting ...elements involved in the transcriptional regulation of TIMP-2. The first is an inverted CCAAT box located at position −73 to −69 in the TIMP-2 promoter that binds the transcription factor NF-Y. The second is a GAGGAGGGGG motif located at position −107 to −98, that binds the transcription factors Sp1 and Sp3. NF-Y and Sp1 cooperate for the basal transcription activity of the promoter. We then determined that TIMP-2 is transcriptionally up-regulated by cAMP analogs. Up-regulation of TIMP-2 by dibutyryl cAMP is a delayed response that requires de novo protein synthesis and does not affect RNA stability. The NF-Y and the Sp1 binding site are both involved in cAMP-dependent up-regulation of TIMP-2. Whereas NF-Y is essential for cAMP mediated regulation, Sp1 alone is not sufficient but enhances the activity of NF-Y. Dibutyryl cAMP has no effect on the expression of MMP-2 and MMP-9 and switches the MMP-TIMP balance in favor of the inhibitor.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Ethnopharmacological surveys conducted in Morocco allowed us to identify many plants species, the most prescribed and used in traditional medicine to treat cancer. From these species, we chose to ...study Mesembryanthemum nodiflorum. We prepa-ed various extracts (alkaloid, cyclohexane, dichloromethane and methanolic) of the Mesembryanthemum nodiflorum aerial parts, the phytochemical studies revealed that the plant contains sterols, sapogenines, triterpenes, tannins and alkaloids. The chemical analysis of cyclohexane extract results in the identification of known con-stituents and the alkaloid extract has been studied by different chromatographic methods to isolate many fractions and to study their chemical composition. These investigations revealed the presence of hordenin. Cytotoxic activities were screened by an in vitro assay system of growth inhibition against two human cancer cell line, namely breast cancer cell line (MCF7) and cervix adenocarcinoma (HeLa), and the results demonstrated that all various extract of Mesembryanthmum nodiflrum did not show significant cytotoxic activity on MCF and Hela cells, at concentrations ranging from 31.25 to 1000 μg/ml. The antioxidant activity of various extracts of M. nodiflo-rum was evaluated by DPPH test and showed that all extract exhibited higher radical scavenging activity, as to standard used, Trolox. The dichlorometh-ane extract of Mesembryanthemum nodiflorum present an anti-radical activity esti-mated to 94.39 ±0.51% (p<0.001). These results suggest that the products of Mese-mbryantemum nodiflorum may provide a new therapeutic avene.
We report on theoretical, numerical and experimental study of a new form of instability in a nonlinear fiber. This process of higher-order modulation instability arises from the nonlinear ...superposition of elementary instability dynamics.
Bone resorption in mice involves the degradation of extracellular matrix. Whereas several proteases seem to be implicated in this process, it becomes increasingly clear that matrix metalloproteinases ...(MMPs), amongst them especially MMP-13 and MMP-3, play an essential role. We have purified MMP-13 and MMP-3 from mouse calvariae-conditioned media by differential fractionation and analyzed their collagenolytic, caseinolytic, gelatinolytic and proteoglycanolytic activities. It could be shown that in mouse calvariae-conditioned media most of the measured enzyme activities were due to MMP-13, although zymographies revealed that MMP-3, MMP-2, MMP-9 as well as TIMPs were present too. MMP-13 and MMP-3 proteins were detected and their enzyme activities were neutralized by specific polyclonal antisera. Furthermore, it was demonstrated that in cultures of mouse calvariae the production of MMP-13 was induced by the potent MMP-stimulator heparin and by parathyroid hormone (PTH), whereas the levels of MMP-3 remained unchanged. Although PTH-induced bone resorption was inhibited by calcitonin treatment, MMP-13 mRNA and protein expression were not significantly altered by this hormone. Together with previous observations, these results indicate that PTH regulates bone resorption through MMP-13, but not by MMP-3, and that its reversion by calcitonin involves neither of the two enzymes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We report experimental observation of optical rogue wave extreme value fluctuations due to pump-signal noise transfer in a fibre Raman amplifier. Experimental results are in good agreement with ...numerical simulations.
A cDNA encoding mouse stromelysin 1 was cloned and the 1740-bp sequence was determined. The deduced amino acid (aa) sequence was compared with stromelysin 1 sequences of other mammals. Comparison ...with a previously published incomplete aa sequence of mouse stromelysin 1 revealed three single aa differences.
Summary form only given. Modulation instability (MI) is a ubiquitous process in which a weak field is exponentially amplified through a balance between dispersive and nonlinear effects. In ...single-mode scalar optical fibers, the positive Kerr nonlinearity phase-mismatch can be compensated by anomalous second-order dispersion, a process known as MI2. But phase-matched solutions can also exist in normal second-order dispersion region, thanks to negative even higher-order terms 1. This process, that we label MI4, gives rise to a pair of narrow sidebands widely detuned far from the pump. MI may grow spontaneously from broadband noise and is usually the main process involved in the early stages of most supercontinuum (SC) generation. Because of its stochastic nature, MI creates strong fluctuations of spectral power, especially near the SC edges. In the time domain, these fluctuations manifest as so-called optical rogue waves, both in the MI2 2 and MI4 3 cases. Active methods based on stimulating the MI2 process have already been proposed 4. However, in the configuration based on MI4, no experiments or numerical works have focused on the study of fluctuations and their reduction.For the first time, the large fluctuations of an SC generated from MI4 are highlighted and a method to mitigate them is proposed and validated. The experimental setup is sketched in Fig. 1(a) and relies on a Q-switch Nd-YAG laser emitting sub-nanosecond pulses. Pump pulses are combined with one or two continuous-wave seeds in the C-band corresponding to the Stokes MI-4 gain bandwidth of a 2 m long photonic crystal fiber. Output spectra as well as the statistical fluctuations after a narrowband filter are experimentally recorded and summarized in Fig. 1(b-c). Contrary to the MI2 case, stimulating the MI4 process with a single seed does not allow to significantly reduce fluctuations. We have found that this can be explained by the spontaneous cascaded MI2 process arising from the amplified seed in the vicinity of the MI4 gain band 5. Therefore, two seeds are required to stimulate both the MI4 and the subsequent MI2, which results in an overall stabilization of the SC. This concept is validated from both experiments and numerical simulations. Fig 1(d) demonstrates that the spontaneous MI2-induced sideband (Fig. 1d2) can be efficiently mitigated by the double seeding scheme (Fig. 1d3). Consequently, the level of fluctuations affecting shot-to-shot records is drastically reduced (Figs. 1e) and numerical simulations based on the extended nonlinear Schrödinger equation reproduce the experimental stability improvement of the continuum source.
In this work, we provide a theoretical and experimental description of the adiabatic transition from an arbitrary low-energy initial condition to the asymptotic similariton state.
We demonstrate polarization insensitive FWM-based wavelength conversion of 40Gb/s DPSK signals in a SiGe waveguide, with 0.42-dB polarization-dependent loss. A 1.5-dB Dower nenaltv was measured at a ...BER of 10 -9 .
Using a cDNA probe, two genomic clones were obtained encoding the human tissue inhibitor of metalloproteinases-3 (TIMP-3). Analysis of these clones showed that they contained four distal exons and ...three introns of the gene. Although the intron-exon structure is similar to that of the
timpl gene, the first intron of the
timp3 gene is much longer, being at least 17.5 kb in size.
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