The role of adipokines in the improvement of diabetic and cardiovascular risk factors within a 52-week weight-loss programme for obesity.

BACKGROUND: Obesity is an independent risk factor for cardiovascular disease and diabetes weight reduction not only reduces the risk for these diseases but leads to an alteration of the circulating adipokine levels. The aim of our study was to evaluate the effect of weight loss and lifestyle changes implemented in the form of the interdisciplinary weight management programme Optifast52® on cardiovascular and diabetic risk factors and on key adipokines. METHODS: 72 morbidly obese patients were included in the programme, which consisted of a very low-calorie diet followed by incremental food introduction and dietary stabilisation, accompanied by medical surveillance, physical activity, dietary counselling and psychological support. At baseline, and after 14, 26 and 49 weeks, risk factor profiles and adipokine levels were evaluated. RESULTS: 43 patients completed the programme with an average weight reduction of about 20%. Significant improvement was observed in the lipid and diabetic laboratory panels of all patients. In addition, adiponectin levels increased significantly (7.79 vs. 12.38µg/ml, p<0.001), while leptin levels decreased (7.29 vs 3.09ng/ml, p<0.001) during the course of the programme. CONCLUSION: In this study, Optifast52®, a multidisciplinary programme focusing on diet and lifestyle changes, was found not only to affect a decrease in parameters associated with diabetes and cardiovascular disease, but also to ameliorate in part the obesity-related imbalance of pro- and anti-inflammatory adipokines.

Selective non-steroidal glucocorticoid receptor agonists attenuate inflammation but do not impair intestinal epithelial cell restitution in vitro.

INTRODUCTION: Despite the excellent anti-inflammatory and immunosuppressive action of glucocorticoids (GCs), their use for the treatment of inflammatory bowel disease (IBD) still carries significant risks in terms of frequently occurring severe side effects, such as the impairment of intestinal tissue repair. The recently-introduced selective glucocorticoid receptor (GR) agonists (SEGRAs) offer anti-inflammatory action comparable to that of common GCs, but with a reduced side effect profile. METHODS: The in vitro effects of the non-steroidal SEGRAs Compound A (CpdA) and ZK216348, were investigated in intestinal epithelial cells and compared to those of Dexamethasone (Dex). GR translocation was shown by immunfluorescence and Western blot analysis. Trans-repressive effects were studied by means of NF-κB/p65 activity and IL-8 levels, trans-activation potency by reporter gene assay. Flow cytometry was used to assess apoptosis of cells exposed to SEGRAs. The effects on IEC-6 and HaCaT cell restitution were determined using an in vitro wound healing model, cell proliferation by BrdU assay. In addition, influences on the TGF-ß- or EGF/ERK1/2/MAPK-pathway were evaluated by reporter gene assay, Western blot and qPCR analysis. RESULTS: Dex, CpdA and ZK216348 were found to be functional GR agonists. In terms of trans-repression, CpdA and ZK216348 effectively inhibited NF-κB activity and IL-8 secretion, but showed less trans-activation potency. Furthermore, unlike SEGRAs, Dex caused a dose-dependent inhibition of cell restitution with no effect on cell proliferation. These differences in epithelial restitution were TGF-ß-independent but Dex inhibited the EGF/ERK1/2/MAPK-pathway important for intestinal epithelial wound healing by induction of MKP-1 and Annexin-1 which was not affected by CpdA or ZK216348. CONCLUSION: Collectively, our results indicate that, while their anti-inflammatory activity is comparable to Dex, SEGRAs show fewer side effects with respect to wound healing. The fact that SEGRAs did not have a similar effect on cell restitution might be due to a different modulation of EGF/ERK1/2 MAPK signalling.

Isothiocyanate sulforaphane inhibits protooncogenic ornithine decarboxylase activity in colorectal cancer cells via induction of the TGF-ß/Smad signaling pathway.

SCOPE: The objective of this study was to elucidate molecular mechanisms behind the antitumor activities of the isothiocyanate sulforaphane (SFN) in colorectal cancer cells. METHODS AND RESULTS: Cell growth was determined by BrdU incorporation and crystal violet staining. Protein levels were examined by Western blot analysis. Ornithine decarboxylase (ODC) activity was assayed radiometrically. Reverse transcriptase-PCR was used for measuring mRNA expression. For reporter gene assays plasmids were transfected into cells via lipofection and luciferase activity was measured luminometrically. Acetyl-histone H3 and H4 chromatin immunoprecipitation (ChIP) assays were performed followed by PCR with TGF-ß-receptor II promoter specific primers. We could show that SFN-mediated cell growth inhibition closely correlates with a dose-dependent reduction of protein expression and enzymatic activity of ODC. This effect seems to be due to reduced protein levels and transactivation activity of transcription factor c-myc, a direct regulator of ODC expression, as a consequence of SFN-induced TGF-ß/Smad signaling. The coherency of these results was further confirmed by using TGF-ß receptor kinase inhibitor SB431542, which largely abolishes inhibitory effects of SFN on both, ODC activity and cell growth. CONCLUSION: Since elevated ODC enzyme activity is associated with enhanced tumor development, SFN may be a dietary phytochemical with potential to prevent carcinogenesis.

Peroxisome proliferator-activated receptor gamma as a molecular target of resveratrol-induced modulation of polyamine metabolism.

Previous results indicate that the polyphenol resveratrol inhibits cell growth of colon carcinoma cells via modulation of polyamine metabolic key enzymes. The aim of this work was to specify the underlying molecular mechanisms and to identify a possible role of transcription factor peroxisome proliferator-activated receptor gamma (PPARgamma). Cell growth was determined by bromodeoxyuridine incorporation and crystal violet staining. Protein levels were examined by Western blot analysis. Spermine/spermidine acetyltransferase (SSAT) activity was determined by a radiochemical assay. PPARgamma ligand-dependent transcriptional activity was measured by a luciferase assay. A dominant-negative PPARgamma mutant was transfected in Caco-2 cells to suppress PPARgamma-mediated functions. Resveratrol inhibits cell growth of both Caco-2 and HCT-116 cells in a dose- and time-dependent manner (P < 0.001). In contrast to Caco-2-wild type cells (P < 0.05), resveratrol failed to increase SSAT activity in dominant-negative PPARgamma cells. PPARgamma involvement was further confirmed via ligand-dependent activation (P < 0.01) as well as by induction of cytokeratin 20 (P < 0.001) after resveratrol treatment. Coincubation with SB203580 abolished SSAT activation significantly in Caco-2 (P < 0.05) and HCT-116 (P < 0.01) cells. The involvement of p38 mitogen-activated protein kinase (MAPK) was further confirmed by a resveratrol-mediated phosphorylation of p38 protein in both cell lines. Resveratrol further increased the expression of PPARgamma coactivator PGC-1alpha (P < 0.05) as well as SIRT1 (P < 0.01) in a dose-dependent manner after 24 hours of incubation. Based on our findings, p38 MAPK and transcription factor PPARgamma can be considered as molecular targets of resveratrol in the regulation of cell proliferation and SSAT activity, respectively, in a cell culture model of colon cancer.

Cationic lipid-protamine-DNA (LPD) complexes for delivery of antisense c-myc oligonucleotides.

In the present study, cationic lipid-peptide-DNA-complexes (LPDs) consisting of AH-Chol-liposomes and protamine-phosphodiester-oligonucleotide-particles (proticles) were introduced as carriers for antisense therapy. The LPDs were physically characterized, and a possible mechanism for adsorption of oligonucleotides (ODNs) was suggested. An increase in stability of ODNs against DNase I and serum nuclease digestion by these carriers was demonstrated. The hydrodynamic diameter increased after incubation with FCS which could be attributed to a protein coating of the particle surface. However, in cell culture medium lower particle sizes of the complexes occurred. In an antisense c-myc in vitro model, the effect of LPDs was tested using U937 cells. The C-MYC level was reduced after treatment of these antisense ODN carrier complexes. Furthermore, no changes in target mRNA concentration of the treated cells was found by reverse transcription and competitive multiplex-PCR.