Nachhaltige Ernährung – Weiterentwicklung fachwissenschaftlich-fachpraktischer Lehrveranstaltungen an der Hochschule

Das vorgestellte Forschungs- und Entwicklungsprojekt zielt darauf ab, das Thema Ernährung und Nachhaltigkeit in der Ausbildung von Lehrpersonen zielgruppenorientiert auszubauen. Die Weiterentwicklung der entsprechenden Lehrveranstaltung folgt einem Baukastenprinzip; Basis für die Entwicklung und Evaluationsmethode sind Erhebungen mit einem hierfür konzipierten Fragebogen, der das anwendungsorientierte Fachwissen zu diesem Thema erfasst. (DIPF/Orig.

Fachbezogene moralische Überzeugungen von Lehrpersonen in der Ernährungs- und Verbraucherbildung (EVB)

Der Beitrag geht der Frage nach, ob es erforderlich sei, dass Lehrpersonen der Ernährungs- und Verbraucherbildung im Kontext einer Bildung für Nachhaltige Entwicklung bestimmte moralische Überzeugungen (Beliefs) vertreten. Die Frage wird auf professionstheoretischer und fachdidaktischer Basis diskutiert und eine stärkere Verflechtung von Beliefs und professionellem Wissen vorgeschlagen. (DIPF/Orig.

An aqueous birch leaf extract of Betula pendula inhibits the growth and cell division of inflammatory lymphocytes

Ethnopharmacological relevance: Leaf extracts of Betula pendula have been traditionally used for the treatment of patients with rheumatoid arthritis (RA) or osteoarthritis

The MAPK pathway signals telomerase modulation in response to isothiocyanate-induced DNA damage of human liver cancer cells.

4-methylthiobutyl isothiocyanate (MTBITC), an aliphatic, sulphuric compound from Brassica vegetables, possesses in vitro and in vivo antitumor activity. Recently we demonstrated the potent growth inhibitory potential of the DNA damaging agent MTBITC in human liver cancer cells. Here we now show that MTBITC down regulates telomerase which sensitizes cells to apoptosis induction. This is mediated by MAPK activation but independent from production of reactive oxygen species (ROS). Within one hour, MTBITC induced DNA damage in cancer cells correlating to a transient increase in hTERT mRNA expression which then turned into telomerase suppression, evident at mRNA as well as enzyme activity level. To clarify the role of MAPK for telomerase regulation, liver cancer cells were pre-treated with MAPK-specific inhibitors prior to MTBITC exposure. This clearly showed that transient elevation of hTERT mRNA expression was predominantly mediated by the MAPK family member JNK. In contrast, activated ERK1/2 and P38, but not JNK, signalled to telomerase abrogation and consequent apoptosis induction. DNA damage by MTBITC was also strongly abolished by MAPK inhibition. Oxidative stress, as analysed by DCF fluorescence assay, electron spin resonance spectroscopy and formation of 4-hydroxynonenal was found as not relevant for this process. Furthermore, N-acetylcysteine pre-treatment did not impact MTBITC-induced telomerase suppression or depolarization of the mitochondrial membrane potential as marker for apoptosis. Our data therefore imply that upon DNA damage by MTBITC, MAPK are essential for telomerase regulation and consequent growth impairment in liver tumor cells and this detail probably plays an important role in understanding the potential chemotherapeutic efficacy of ITC

Effect of specific MAPK inhibitors on telomerase.

<p>For specific inhibition of p38 activation, 10 µM SB203580 or 20 µM SB202190, of JNK activation, 5 µM SP600125 or 20 µM JNK inhibitor V were used, respectively. 10 µM U0126 or 40 µM PB98059 were used for ERK1/2 inhibition. Cells were pre-treated with the inhibitors and subsequently exposed to MTBITC or the solvent control (0.1% DMSO). <b>a)</b> Immunoblot analysis shows effective inhibition of the target proteins. β-actin was used as loading control <b>b)</b> Pre-treated cells were analysed for full length hTERT mRNA expression after 1 h exposure to 25 µM MTBITC. PBDG was used as reference gene. mRNA expression was calculated relative to the corresponding solvent control (n = 3). <b>c+d)</b> Pre-treated cells were assayed for telomerase enzyme activity after 3 h (d) or 24 h (e) MTBITC exposure using the TRAP-ELISA assay. Telomerase activity was calculated relative to the corresponding solvent control; bars are mean ± SEM (n = 3). Inhibitors 3×: combination of SB203580, SP600125 and U0126.</p

MAPK are activated upon MTBITC exposure.

<p>Cells were lysed and total lysate subjected to immunoblotting. <b>a)</b> HCC cells were treated with 25 µM MTBITC or the solvent control (0.1% DMSO) for the indicated time points. HepG2 cells (<b>b</b>) or human hepatocytes (<b>c</b>) were treated with MTBITC for 3 h at the indicated concentrations. Representative blots are shown. Each blot was reprobed with anti-β-actin antibody to ensure equal protein loading. <b>d)</b> Primary normal human hepatocytes were not adversely affected by MTBITC, as evident in representative pictures, captured by light microscopy. SC: solvent control = 0.1% DMSO. +, positive control = 0.01% triton X-100. Bar = 100 µm. All panels have the same magnification.</p

Apoptosis induction and telomerase loss in HepG2 cells are independent from ROS production.

<p><b>a)</b> Effect of MTBITC on ROS production in adherent growing cells. Cells were exposed to MTBITC for 1 to 6 h, washed thoroughly with PBS and subsequently exposed to 100 µM spin probe CMH in Krebs-Hepes buffer. ROS were then quantified using ESR spectrometry. Positive control: 100 µM menadione. The pictures display the middle peak of ESR spectra of CMH spin probe labelled samples. Bars are mean ± SD, n = 3. <b>b)</b> Representative immunoblot for HNE Lys-adducts after exposure to MTBITC or DMSO for different time points. Total lysate of HepG2 cells was subjected to immunoblotting using an anti-HNE Lys antibody. Exposure of cells to HNE for 80 min. was used as positive control. The blot was reprobed with anti-β-actin antibody to ensure equal protein loading. <b>c+d)</b> Effect of NAC pre-treatment. HepG2 cells were pre-treated with NAC for 1 h, washed with PBS and subsequently exposed to 25 µM MTBITC or 0.1% DMSO for another 24 h. Cells were then prepared for (c) TRAP analysis or (d) flow cytometric analysis of the mitochondrial membrane potential (MMP) as parameter for apoptosis; *p≤0.05. M: 50 bp DNA marker; 1) 0.1% DMSO 2) 25 µM MTBITC 3) 5 mM NAC +0.1% DMSO,4) 5 mM NAC +25 µM MTBITC 5) cell lytic buffer 6) destilled water 7) 0.1% DMSO, heat treated. <b>e)</b> Effect of 25 µM MTBITC on mtDNA damage after 1 or 24 h exposure of HepG2 cells. Agarose gel electrophoresis of amplified mtDNA multiplex PCR products is shown in representative image details. Each lane contains amplification products obtained with mtDNA from one single cell using specific PCR primers. As positive control for mtDNA damage, cells were exposed to 10 min UV irradiation. f<b>)</b> Representative pictures of beta-galactosidase staining of HCC cells after exposure to MTBITC for 72 h, captured by light microscopy. beta-galactosidase positive cells are reflected by dark color of the cells. SC: solvent control = 0.1% DMSO. Scale bar = 200 µm, all panels have the same magnification.</p

DNA damage leads to transient hTERT mRNA expression in HepG2 cells.

<p><b>a)</b> Cells were exposed to 25 µM MTBITC or the solvent control (0.1% DMSO) for 1 h and subsequently analyzed for their DNA damage using the comet assay. The % tail DNA was used for damage quantification. Bars are mean ± SD, n = 3. Cells exposed to 100 µM benzo(a)pyrene (B(a)P) for 1 h were used as positive control. <b>b)</b> Expression of full length hTERT mRNA after exposure to MTBITC or solvent control for 1 h to 96 h was analysed by RT-PCR. PBDG was used in all experiments as reference gene. mRNA expression was calculated relative to the solvent control; bars are mean ± SD (n = 3).</p

Sequences and fragment length of primer pairs used for mtDNA amplification.

*<p>according to: Parson et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053240#pone.0053240-Wada1" target="_blank">[37]</a> ** according to: Eichmann et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053240#pone.0053240-AlfonsoDeMatte1" target="_blank">[38]</a> *** according to: Andréasson et al. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053240#pone.0053240-Potapova1" target="_blank">[39]</a>.</p