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We previously isolated islet stellate cells (ISCs) from healthy Wistar rat islets. In the present study, we isolated “already primed by diabetic environment” ISCs from islets of Goto-Kakizaki rats, determined the gene profile of these cells, and assessed the effects of these ISCs on beta-cell function and survival. We detected gene expression of ISCs by digital gene expression. INS-1 cell proliferation, apoptosis, and insulin production were measured after being treated with ISCs supernatant (SN). We observed the similar expression pattern of ISCs and PSCs, but 1067 differentially expressed genes. Insulin production in INS-1 cells cultured with ISC-SN was significantly reduced. The 5-ethynyl-2′-deoxyuridine-positive INS-1 cells treated with ISC-SN were decreased. Propidium iodide- (PI-) positive INS-1 cells were 2.6-fold higher than those in control groups. Caspase-3 activity was increased. In conclusion, ISCs presented in fibrotic islet of GK rats might be special PSCs, which impaired beta-cell function and proliferation and increased beta-cell apoptosis. [ABSTRACT FROM AUTHOR]

Objective: Metabolic effects of different caloric regimens were investigated in nonsurgical, medical patients with multiple-organ failure (MOF).Design: Seven total parenteral nutrition (TPN) regimens were administered, differing in amount (14, 28, and 56 kcal/kg per day, i.e., hypo-, iso-, and hypercaloric nutrition, respectively) and distribution [carbohydrates (COH), amino acids (AA), long-chain and medium-chain triglycerides (LCT/MCT)] of calories. Each regimen was administered over 12 h. Metabolism was monitored by energy expenditure (EE), body temperature (BT), protein breakdown (PB), and blood glucose and serum lactate levels. Measurements were started within 2 days of MOF onset.Setting: The study was conducted in a medical intensive care unit.Patients: Twenty patients with MOF on mechanical ventilation (mean Apache II score x = 26) were investigated.Measurements and Results: The mean values of the EE (x = 31 kcal/kg per day), BT (x = 38 degrees C), PB (x = 1.5 g/kg per day), and lactate (x = 2.0 mmol/l) and glucose level (x = 222 mg/dl) parameters were elevated. EE, BT, and lactate and glucose levels were significantly lower under hypocaloric nutrition than during iso- and hypercaloric nutrition (p < 0.01). Differences in the metabolic effects of LCT and MCT were not significant. PB was significantly elevated under hypercaloric nutrition (p < 0.01). Protein balance was positive under hypercaloric nutrition, and negative under iso- and hypocaloric nutrition.Conclusions: In nonsurgical, medical patients neither hypercaloric nor isocaloric nutritional support prevented protein catabolism; in contrast, they enhanced the metabolic burden measured by EE, thermogenesis, urea production rate, and glucose and lactate levels. A hypocaloric regimen is therefore recommended for these patients during the early phase of MOF. [ABSTRACT FROM AUTHOR]

In type 2 diabetes mellitus, pancreatic stellate cells (PSCs) are present within and surrounding pancreatic islets and may cause progressive fibrosis and deterioration of pancreatic beta cell function. However, it is unknown whether pancreatic beta cells influence the biological behavior of PSCs. In the present study, we examined the impact of pancreatic beta cells on the proliferation, migration and extracellular matrix (ECM) production of PSCs. PSCs were treated with conditioned media from INS-1 cells (supernatant, SN). Although the proliferation of PSCs incubated with INS-1-SN was increased compared to control, INS-1-SN treatment induced matrix metalloproteinase-2 activity and reduced the production of ECM and TGF-β1. In addition, PSCs treated with INS-1-SN reduced the secretion of cytokines that are known to mediate pancreatic beta cell death, such as FADD, Fas, IFN-γ, IL-1, TNF-α, and TRAIL. Our findings suggest that pancreatic beta cells may ameliorate islet fibrosis and the progression of islet dysfunction. [ABSTRACT FROM AUTHOR]

Background:Pancreatic stellate cells (PSCs) promote metastasis as well as local growth of pancreatic cancer. However, the factors mediating the effect of PSCs on pancreatic cancer cells have not been clearly identified.Methods:We used a modified Boyden chamber assay as an in vitro model to investigate the role of PSCs in migration of Panc1 and UlaPaCa cells and to identify the underlying mechanisms.Results:PSC supernatant (PSC-SN) dose-dependently induced the trans-migration of Panc1 and UlaPaCa cells, mainly via haptokinesis and haptotaxis, respectively. In contrast to poly-L-lysine or fibronectin, collagen I resembled PSC-SN with respect to its effect on cancer cell behaviours, including polarised morphology, facilitated adhesion, accelerated motility and stimulated trans-migration. Blocking antibodies against integrin α2/β1 subunits significantly attenuated PSC-SN- or collagen I-promoted cell trans-migration and adhesion. Moreover, both PSC-SN and collagen I induced the formation of F-actin and focal adhesions in cells, which was consistent with the constantly enhanced phosphorylation of focal adhesion kinase (FAK, Tyr397). Inhibition of FAK function by an inhibitor or small interference RNAs significantly diminished the effect of PSC-SN or collagen I on haptotaxis/haptokinesis of pancreatic cancer cells.Conclusion:Collagen I is the major mediator for PSC-SN-induced haptokinesis of Panc1 and haptotaxis of UlaPaCa by activating FAK signalling via binding to integrin α2β1. [ABSTRACT FROM AUTHOR]

Background: Pancreatic stellate cells (PSCs) promote metastasis as well as local growth of pancreatic cancer. However, the factors mediating the effect of PSCs on pancreatic cancer cells have not been clearly identified.Methods: We used a modified Boyden chamber assay as an in vitro model to investigate the role of PSCs in migration of Panc1 and UlaPaCa cells and to identify the underlying mechanisms.Results: PSC supernatant (PSC-SN) dose-dependently induced the trans-migration of Panc1 and UlaPaCa cells, mainly via haptokinesis and haptotaxis, respectively. In contrast to poly-L-lysine or fibronectin, collagen I resembled PSC-SN with respect to its effect on cancer cell behaviours, including polarised morphology, facilitated adhesion, accelerated motility and stimulated trans-migration. Blocking antibodies against integrin α2/β1 subunits significantly attenuated PSC-SN- or collagen I-promoted cell trans-migration and adhesion. Moreover, both PSC-SN and collagen I induced the formation of F-actin and focal adhesions in cells, which was consistent with the constantly enhanced phosphorylation of focal adhesion kinase (FAK, Tyr397). Inhibition of FAK function by an inhibitor or small interference RNAs significantly diminished the effect of PSC-SN or collagen I on haptotaxis/haptokinesis of pancreatic cancer cells.Conclusion: Collagen I is the major mediator for PSC-SN-induced haptokinesis of Panc1 and haptotaxis of UlaPaCa by activating FAK signalling via binding to integrin α2β1. [ABSTRACT FROM AUTHOR]

Background: Secreted protein acidic and rich in cysteine (SPARC) is a multi-faceted protein-modulating cell-cell and cell-matrix interactions. In cancer, SPARC can be not only associated with a highly aggressive phenotype, but also acts as a tumour suppressor. The aim of this study was to characterise the function of SPARC and its modulation by fibroblast growth factor receptor (FGFR) 1 isoforms in pancreatic ductal adenocarcinoma (PDAC).Methods and Results: Exogenous SPARC inhibited growth, movement, and migration. ShRNA inhibition of endogenous SPARC in ASPC-1 and PANC-1 cells resulted in increased anchorage-dependent and -independent growth, transwell migration, and xenograft growth as well as increased mitogenic efficacy of fibroblast growth factor (FGF) 1 and FGF2. Endogenous SPARC expression in PANC-1 cells was increased in FGFR1-IIIb over-expressing cells, but decreased in FGFR1-IIIc over-expressing cells. The up-regulation of endogenous SPARC was abrogated by the p38-mitogen-activated protein kinase inhibitor SB203580. SPARC was detectable in conditioned medium of pancreatic stellate cells (PSCs), but not PDAC cells. Conditioned medium of PDAC cells reduced endogenous SPARC expression of PSCs.Conclusion: Endogenous SPARC inhibits the malignant phenotype of PDAC cells and may, therefore, act as a tumour suppressor in PDAC. Endogenous SPARC expression can be modulated by FGFR1-III isoform expression. In addition, PDAC cells may inhibit endogenous SPARC expression in surrounding PSCs by paracrine actions. [ABSTRACT FROM AUTHOR]

The failure of malignant cells to undergo apoptosis is a major obstacle in cancer therapy, and thus identifying the underlining molecules involved therein is imperative for improving patient survival. An important mechanism of drug resistance is cell adhesion-mediated drug resistance (CAM-DR). In this study we identify a novel switch by which glioblastoma multiforme (GBM) cells alter the mode of CAM-DR. In the absence of a microenvironmental cue provided by components of the extracellular matrix (ECM), GBM cells are able to employ an alternative, but equally effective, mode of CAM-DR by forming spheres via cell–cell interactions. Intriguingly, when inhibiting cell–cell interactions in the absence of ECM components, either by low cell density or by inhibition of gap junctions (intercellular connexin tunnels) through chemical inhibition with carbenoxyolone or co-incubation with the connexin-mimicking Gap 27 Cx37,43 peptide, GBM cells were sensitized to tumor necrosis factor-related apoptosis-inducing ligand- and CD95-induced apoptosis. By demonstrating that GBM cells can alternate from one form of CAM-DR (cell-substrate tethering) to another (homocellular cell–cell adhesion) and that inhibition of both forms is necessary for apoptosis sensitization, our findings not only have important implications for novel approaches to restore defective apoptosis programs, but also reveal a novel role of gap junctions in GBM.Oncogene (2008) 27, 5169–5181; doi:10.1038/onc.2008.148; published online 12 May 2008 [ABSTRACT FROM AUTHOR]

Background A broad spectrum of hepatobiliary disorders are found in patients with inflammatory bowel diseases. The aim of the present work was to study interactions between gut and liver in experimental rat models of colitis and small bowel inflammation. Materials and methods Colitis was induced either by trinitrobenzene sulphonic acid or dextran sodium sulphate. Small-bowel inflammation was induced by indomethacin. Bile acid secretion, bile acid pool, and cholesterol 7-α hydroxylase were studied. Cholesterol 7-α hydroxylase protein expression was analysed in the microsomal liver fraction. As portal mediators released form the inflamed gut we measured lipopolysaccharide, tumour necrosis factor-α and interleukin-1β in portal serum. The hepatic inflammatory response was evaluated by binding activity of nuclear factor-κB, activator protein-1 and α-2-macroglobulin. Results Increased bile acid secretion, total bile acid content in gut and liver (bile acid pool size), and hepatic cholesterol 7-α hydroxylase protein and mRNA levels were found in the two colitis models associated with only a minor hepatic acute phase and cytokine response. In contrast, during indomethacin-induced small-bowel inflammation bile acid secretion, pool size, and cholesterol 7-α hydroxylase decreased in parallel to a strong hepatic cytokine and acute phase response. Conclusions Colitis without portal cytokine release and acute phase reaction shows an induction of bile acid secretion, pool size, and cholesterol 7-α hydroxylase. In contrast, intestinal inflammation after indomethacin treatment is associated with an acute phase response and a repression of bile acid synthesis. [ABSTRACT FROM AUTHOR]

Objectives and methods: In idiopathic pulmonary fibrosis (IPF), proliferation of fibroblasts and increased matrix deposition result in pulmonary damage and respiratory insufficiency. We cultured human fibroblasts from lung biopsies of healthy adults and of three patients with IPF (histologically usual interstitial pneumonitis, UIP) in order to compare proliferation ([³H]thymidine incorporation, cell count) and matrix protein expression (immune fluorescence, quantification of fibronectin synthesis using time-resolved immune fluorescence) of normal and UIP fibroblasts in response to various growth factors. Findings: The growth factors platelet-derived growth factor-BB (PDGF). epidermal growth factor (EGF), insulin growth factor-1 (IGF-1), insulin-like growth factor-2 (IGF-2), tumor necrosis factor α (TNFα), Transforming growth factor-β (TGFβ1), and fibroblast growth factor-2 (FGF-2) stimulate proliferation of normal lung fibroblasts significantly more than proliferation of UIP fibroblasts. Immunofluorescence reveals extensive expression of collagen I, collagen III, and fibronectin induced by serum, TGFβ1, and TNFα. This expression is more pronounced in UIP fibroblasts than in normal fibroblasts. Quantification of fibronectin synthesis reveals an enhanced fibronectin synthesis by UIP fibroblasts in response to PDGF, EGF, IGF-1, IGF-2, TNFα, TGFβ1, and FGF-2). Conclusions: Fibroblasts from normal and UIP lungs differ in their response to growth factors: Whereas normal fibroblasts show a predominantly proliferative response, UIP fibroblasts show an enhanced synthetic activity. Different fibroblast responses may contribute to progressive pulmonary fibrosis in patients with UIP. [ABSTRACT FROM AUTHOR]

The role of nitric oxide (NO) in the pathophysiology of inflammatory bowel diseases (IBD) is controversially discussed. The aim of the present study was to investigate the role of NO inhibition in the acute phase of rat 2,4,6-trinitrobenzenesulphonic acid (TNB)-colitis. To inhibit NO synthesis we used aminoguanidine (AG) as a selective inhibitor of inducible nitric oxide synthase (iNOS). TNB-colitis was induced in rats with and without pretreatment with AG (200 mg kg-1 body weight in the drinking water). The severity of colitis was observed over a period of 7 days. On days 1 and 2, AG reduced concentrations of plasma nitrate and nitrite as well as of portal 6-keto-prostaglandin 1α. AG pretreatment increased colonic damage and inflammatory response, assessed by colonic myeloperoxidase and serum lactate dehydrogenase activity, macroscopic damage score, tumour necrosis factor-α concentration in stool and colonic glutathione content. The AG-treated group showed a higher and prolonged nuclear factor κB (NF-κB)/Rel binding activity in the colon. We conclude that NOS inhibition by AG is not beneficial in acute intestinal inflammation. With regard to appropriate therapeutic strategies, NF-κB/Rel activation might be a more suitable target. [ABSTRACT FROM AUTHOR]

Summarizes several aspects that have emerged concerning composition, formation and regulation of the extracellular matrix in human pancreatic diseases and in experimental models of pancreatic fibrosis. Characteristics of chronic inflammatory diseases of the pancreas; Animal models for pancreatic fibrogenesis.

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KC elaborate factors which induce in FSC PG-synthesis, proliferation and transformation. The factor stimulating PG-synthesis is preliminary characterized as a heat-sensitive (>80 °C) protein with a molecular mass higher than 20 to 25 kd, which does not belong to the group heparin-binding growth factors and which is not identical with interleukin-1 and tumor necrosis factor α, respectively. The secretion of such factors (fibrogenic mediators) by KC activated in situ during tissue injury will be important for the induction of the synthesis and deposition of connective tissue in hepatic injury and their immunochemical determination might prove useful for the diagnosis of the activity of the fibrotic process. [ABSTRACT FROM AUTHOR]