Folia Biologica最新文献

The effects of octadecylamide of alginic acid (amidated alginate) and tetrahydrolipstatin on serum and hepatic cholesterol, and the faecal output of fat and sterols, were investigated in rats. Amidated alginate is a sorbent of lipids, tetrahydrolipstatin is an inhibitor of pancreatic lipase. Rats were fed diets containing cholesterol and palm fat at 10 and 70 g/kg, respectively. Palm fat was provided by coconut meal. Amidated alginate at 40 g/kg diet significantly decreased serum total cholesterol, low-density lipoprotein and hepatic cholesterol, and hepatic lipids and increased the faecal output of fat and coprostanol. Tetrahydrolipstatin at 300 mg/kg diet significantly decreased low-density lipoprotein cholesterol and hepatic lipids and increased the faecal output of fat. The intake of feed was not significantly influenced; however, the weight gains in rats fed amidated alginate were lower than in rats of the control group. Both amidated alginate and tetrahydrolipstatin modified the fatty acid profile in excreta lipids. Concentrations of saturated fatty acids were decreased and those of unsaturated fatty acids increased. Despite different modes of action, amidated alginate and tetrahydrolipstatin were equally efficient in removing the dietary fat from the body.

Clostridial collagenases are essential biotechnological tissue dissociation agents owing to their ability to cleave different types of collagen. Standardization of collagenase-based protocols has been hampered by impurities in products manufactured from Clostridium histolyticum. To enhance the purification process, we produced recombinant collagenase classes G and H, taking advantage of the Escherichia coli expression system. The respective gene sequences were derived from C. histolyticum and modified by addition of a C-terminal polyhistidine tag. Harvested bacteria were lysed and the collagenase protein was affinity purified using a His-tag column. The purity, identity, integrity of the eluted collagenases G and H were determined by SDS electrophoresis and Western blot. The proteolytic activity of the collagenase G and H blend (rColGH) was determined by the standard FALGPA assay. The tissue dissociation activity was verified using a standardized method for isolation of rat pancreatic islets. Biocompatibility of the blend was validated by a standardized viability assay on the isolated islets. Two batches of rColGH were produced and compared to a commercially available collagenase. Based on our results, we conclude that rColGH is a functional and non-toxic novel recombinant collagenase worth further characterization and blend optimization in order to make it a competitive commercial product.

Hypoxia leads to post-treatment metastasis and recurrences of cancer via the epithelial-mesenchymal transition (EMT). Radiotherapy itself may also contribute to the acquisition of EMT phenotypes. Despite extensive studies on the EMT driven by either hypoxia or radiation stimuli, the molecular mechanisms characterizing these EMT events remain unclear. Thus, we aimed to evaluate the differences in the molecular pathways between hypoxia-induced EMT (Hypo-EMT) and radiation-induced EMT (R-EMT). Further, we investigated the therapeutic effects of HIF-1α inhibitor (LW6) on Hypo-EMT and R-EMT cells. A549 cells, lung adenocarcinoma cell line, acquired enhanced wound-healing activity under both hypoxia and irradiation. Localization of E-cadherin was altered from the cell membrane to the cytoplasm in both hypoxia and irradiated conditions. Of note, the expression levels of vimentin, one of the major EMT markers, was enhanced in irradiated cells, while it decreased under hypoxia condition. Importantly, LW6 significantly blocked EMT-related malignant phenotypes in both Hypo-EMT cells and R-EMT cells with concomitant re-location of E-cadherin onto the cell membrane. Moreover, LW6 deflected stress responsive signalling, JNK, activated sustainably under hypoxic condition, and the blockage of JNK impaired EMT phenotypes. Together, this work demonstrated the molecular events underlying Hypo-EMT and R-EMT, and highlighted HIF-1α as a therapeutic target not only in Hypo- EMT, but also in R-EMT.

This study was aimed to investigate the impact of serine/arginine-rich splicing factor 3 (SRSF3) on the proliferation and migration of gastric cancer (GC) cells. SRSF3 levels in GC tissues and cell lines were measured by Western blotting. Functional assays were used for evaluation of GC cell proliferation, migration and invasion. The PI3K/AKT/mTOR pathway was then examined by Western blotting. SRSF3 exhibits abnormal expression for the significantly increased levels in GC. SRSF3 knockdown significantly suppressed GC progression. SRSF3 knockdown significantly inhibited activation of PI3K/AKT/mTOR signalling. Inhibition of SRSF3 alleviates proliferation and migration of GC cells, and this process is mediated by inactivation of PI3K/ AKT/mTOR signalling. Targeting SRSF3 may be a promising strategy to combat GC.

Osteosarcoma (OS), a severe malignant bone tumour, usually occurs in adolescents and children and has a poor prognosis. Asiatic acid (AA), an active component isolated from Centella asiatica (L.) Urb., exhibits appreciable anti-oxidant and anti-tumour activities. So far, the effects and underlying mechanisms of AA against OS have not been clarified. Here, we explored the anti-tumour effects of AA against human OS and the involved mechanism mediating its actions. To evaluate effects of AA on the cell proliferation of human OS cells, cell viability and colony formation assays were performed. Flow cytometry was used to evaluate apoptosis in OS cells exposed to AA and mitochondrial membrane potential. Western blotting and RT-PCR were applied to determine expression of the relevant proteins and their mRNA levels. Our explorations showed that AA inhibits proliferation of human OS cells in a concentration- and time-dependent manner, and induces apoptosis of OS cells by the intrinsic (mitochondrial) pathway. Importantly, we found that inhibition of the AA-induced phosphorylation of JAK2/STAT3 signalling molecules and the decrease in MCL-1 contributed to the anti-tumour efficacy of AA. Collectively, our results suggest that AA could evoke mitochondrial- induced apoptosis in human OS cells by suppression of the JAK2/STAT3 pathway and MCL-1 expression. These results strongly demonstrate that AA could be a potential anti-tumour agent for OS treatment.

Neuroblastic tumours exhibit heterogeneity, which results in different therapeutic outcomes. Neuroblastoma is categorized into three major risk groups (low, intermediate, high risk). Recent identification of new genes raised the possibility of new biomarkers to identify sub-risk groups. In this retrospective cross-sectional study, we aimed to assess new biomarkers defining the ultra-high-risk subgroup within the high-risk group that differ in clinical situation with very bad prognosis. Twenty-five low- and 29 high-risk groups of patients were analysed for their expression of ALK, ATRX, HIF1a, HIF2a (EPAS), H2AFX, and ETV5 genes at the RNA level. Immunohistochemistry was performed to confirm the protein expression level of ALK. The risk group of patients was determined according to the International Neuroblastoma Risk Group Stratification System. Spearman correlation analysis and Mann-Whitney-U nonparametric test were used to assess the importance of expression levels among the groups. P < 0.05 was considered as significant. Sensitivity of the results was checked by ROC curve analysis. All analysed genes were found to be highly expressed in the high-risk group compared to the low-risk group, except for ETV5. When the ultra-high-risk and highrisk groups were compared, ALK was found to be highly expressed in the ultra-high-risk group. Our results show that ALK may be a candidate gene whose mRNA expression levels can distinguish the ultrahigh- risk subgroup of patients in the high-risk group of patients with non-familial neuroblastoma.

Platycodin D is an active component isolated from Chinese herb Platycodonis radix with various pharmacological activities, such as antitussive, expectorant, anti-inflammatory, and analgesic effects. Interestingly, platycodin D also exerts anticancer effects against several types of cancer. However, few studies on the anti-tumour effects of platycodin against urinary bladder cancer have been reported. In this study, we explored the anti-tumour effect of platycodin D against human bladder cancer and its mechanisms in vitro and in vivo. We found that platycodin D had significant anti-proliferative effects on four types of cancer cells, especially the 5637 bladder cancer cell line, and exerted these effects by preventing cell cycle progression from G0/G1 to S phase, down-regulating Ki-67 and cyclin D1 protein expression and up-regulating P21 protein expression. Furthermore, platycodin D inhibited 5637 cell migration by decreasing twist-related protein 1 (Twist1) and matrix metallopeptidase 2 (MMP2) expression and exerted significant tumour-suppressive effects in tumour-bearing nude mice. Platycodin D also increased caspase-9, caspase-8, caspase-3, and p53 expression and decreased Bcl-2 expression in tumour tissues. Taken together, our results provide a theoretical basis for application of platycodin D in treating urinary bladder cancer.

Salivary urea is studied as a non-invasive alternative for screening and monitoring of renal diseases. Its high variability prevents a wider clinical use. Animal experiments are needed to identify factors affecting this marker. The aim of this study was to describe the inter-individual variability of salivary urea in healthy mice, establish reference intervals, and analyse the effects of sex, age and body weight. Plasma and saliva samples were obtained from 37 male and 41 female healthy adult CD1 mice aged 13-69 weeks (body weight 22-51 g). The reference interval for salivary urea in heathy mice based on our results is 2.7-8.4 mmol/l (CV = 23 %). Multivariate analysis did not show any significant effect of age, sex, or body weight. In addition, salivary urea did not correlate with its plasma concentrations. The high variability of the promising salivary marker of kidney function in healthy mice requires further research before its use to diagnose or monitor renal failure in animal models of kidney diseases. Other potential confounders should be analysed, including intra-individual and pre-analytical variability. In addition, a normalization factor such as total salivary proteins or salivation rate is likely needed.

Luteoloside (Lute), a bioactive natural ingredient, widely exists in nature and possesses hepatoprotective and hepatocyte proliferation-promoting properties. This study aimed to investigate whether Lute could counteract non-alcoholic fatty liver disease (NAFLD)-caused hepatocyte damage via its stimulation of hepatocyte regeneration efficacy and to explore the involved mechanism. LO2 cells and primary hepatocytes were used to examine the hepatocyte proliferation effects of Lute under physiological conditions and in the palmitic acid (PA)- induced in vitro model of NAFLD. STAT3 and cell cycle-related proteins (cyclin D1, c-myc and p21) were evaluated by Western blot. Under physiological conditions, LO2 cells and primary hepatocytes treated with various concentration of Lute for 12 and 24 h showed increased hepatocyte proliferation, especially with 20 μM treatment for 24 h. More notably, under the model conditions, co-incubation with 20 μM of Lute also markedly reversed PA-induced inhibition of cell proliferation and viability in primary hepatocytes. Mechanistically, Lute could activate STAT3 and subsequently increase cyclin D1 and cmyc expression, which positively regulates cell cycle progression, and decrease expression of p21, an inhibitor of cell cycle progression. Furthermore, Luteinduced hepatocyte proliferation-promoting efficacy was abolished by STAT3 inhibitor stattic. Collectively, Lute can alleviate PA-induced hepatocyte damage via activating STAT3-mediated hepatocyte regeneration.

Gastric cancer is characterized by the presence of high invasion ability, hypoxia and chemoresistance. Previous studies reported that liver X receptor α (LXRα) was involved in epithelial-mesenchymal transition (EMT) of gastric cancer cells. However, hypoxia-mediated EMT and the role of LXRα in gastric cancer remained elusive. In this study, we demonstrated that LXRa mRNA and protein levels were up-regulated by hypoxia treatment and LXRα played an important role in HIF-1 dimer induced-EMT. The putative HIF-1α binding site was identified in the LXRa promoter. Expression of LXRα and HIF-1α was significantly up-regulated in gastric cancer tissues compared to that in normal tissues. More importantly, we noticed that the expression of LXRα and HIF-1α was significantly correlated. Taken together, these data suggested that LXRα is regulated by the activity and accumulation of HIF-1α and contributes to EMT of gastric cancer cells. This suggests that targeting LXRα might be a potential approach for improving survival of gastric cancer patients.