Int. J. Mol. Sci.2014, 15(3), 4088-4103; doi:10.3390/ijms15034088 - published online 6 March 2014 Show/Hide Abstract
Abstract: Previous results on nitric oxide (NO) metabolism after traumatic brain injury (TBI) show variations in NO availability and controversial effects of exogenous nitric oxide synthase (NOS)-inhibitors. Furthermore, elevated levels of the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA) were reported in cerebro-spinal fluid (CSF) after traumatic subarachnoid hemorrhage (SAH). Therefore, we examined whether ADMA and the enzymes involved in NO- and ADMA-metabolism are expressed in brain tissue after TBI and if time-dependent changes occur. TBI was induced by controlled cortical impact injury (CCII) and neurological performance was monitored. Expression of NOS, ADMA, dimethylarginine dimethylaminohydrolases (DDAH) and protein-arginine methyltransferase 1 (PRMT1) was determined by immunostaining in different brain regions and at various time-points after CCII. ADMA and PRMT1 expression decreased in all animals after TBI compared to the control group, while DDAH1 and DDAH2 expression increased in comparison to controls. Furthermore, perilesionally ADMA is positively correlated with neuroscore performance, while DDAH1 and DDAH2 are negatively correlated. ADMA and its metabolizing enzymes show significant temporal changes after TBI and may be new targets in TBI treatment.
Int. J. Mol. Sci.2014, 15(3), 4077-4087; doi:10.3390/ijms15034077 - published online 6 March 2014 Show/Hide Abstract
Abstract: The aim of this study was to investigate the combined influence of diet, menstruation and genetic factors on iron status in Spanish menstruating women (n = 142). Dietary intake was assessed by a 72-h detailed dietary report and menstrual blood loss by a questionnaire, to determine a Menstrual Blood Loss Coefficient (MBLC). Five selected SNPs were genotyped: rs3811647, rs1799852 (Tf gene); rs1375515 (CACNA2D3 gene); and rs1800562 and rs1799945 (HFE gene, mutations C282Y and H63D, respectively). Iron biomarkers were determined and cluster analysis was performed. Differences among clusters in dietary intake, menstrual blood loss parameters and genotype frequencies distribution were studied. A categorical regression was performed to identify factors associated with cluster belonging. Three clusters were identified: women with poor iron status close to developing iron deficiency anemia (Cluster 1, n = 26); women with mild iron deficiency (Cluster 2, n = 59) and women with normal iron status (Cluster 3, n = 57). Three independent factors, red meat consumption, MBLC and mutation C282Y, were included in the model that better explained cluster belonging (R2 = 0.142, p < 0.001). In conclusion, the combination of high red meat consumption, low menstrual blood loss and the HFE C282Y mutation may protect from iron deficiency in women of childbearing age. These findings could be useful to implement adequate strategies to prevent iron deficiency anemia.
Int. J. Mol. Sci.2014, 15(3), 4060-4076; doi:10.3390/ijms15034060 - published online 6 March 2014 Show/Hide Abstract
Abstract: Long non-coding RNA HOTAIR exerts regulatory functions in various biological processes in cancer cells, such as proliferation, apoptosis, mobility, and invasion. We previously found that HOX transcript antisense RNA (HOTAIR) is a negative prognostic factor and exhibits oncogenic activity in hepatocellular carcinoma (HCC). In this study, we aimed to investigate the role and molecular mechanism of HOTAIR in promoting HCC cell migration and invasion. Firstly, we profiled its gene expression pattern by microarray analysis of HOTAIR loss in Bel-7402 HCC cell line. The results showed that 129 genes were significantly down-regulated, while 167 genes were significantly up-regulated (fold change >2, p < 0.05). Bioinformatics analysis indicated that RNA binding proteins were involved in this biological process. HOTAIR suppression using RNAi strategy with HepG2 and Bel-7402 cells increased the mRNA and protein expression levels of RNA binding motif protein 38 (RBM38). Moreover, the expression levels of RBM38 in HCC specimens were significantly lower than paired adjacent noncancerous tissues. In addition, knockdown of HOTAIR resulted in a decrease of cell migration and invasion, which could be specifically rescued by down-regulation of RBM38. Taken together, HOTAIR could promote migration and invasion of HCC cells by inhibiting RBM38, which indicated critical roles of HOTAIR and RBM38 in HCC progression.
Int. J. Mol. Sci.2014, 15(3), 4049-4059; doi:10.3390/ijms15034049 - published online 6 March 2014 Show/Hide Abstract
Abstract: Recent studies have shown that dexmedetomidine exerts an anti-inflammatory effect by reducing serum levels of inflammatory factors, however, the up-stream mechanism is still unknown. The transcription factor NF-κB enters the nucleus and promotes the transcription of its target genes, including those encoding the pro-inflammatory cytokines IL-6 and TNF-α. In this study, we established a rat model that simulates a clinical surgical procedure to investigate the anti-inflammatory effect of perineural administration of dexmedetomidine and the underlying mechanism. Dexmedetomidine reduced the sciatic nerve levels of IL-6 and TNF-α at both the mRNA and protein level. Dexmedetomidine also inhibited the translocation of activated NF-κB to the nucleus and the binding activity of NF-κB. The anti-inflammatory effect is confirmed to be dose-dependent. Finally, pyrrolidine dithiocarbamate also reduced the levels of IL-6 and TNF-α and the activation of NF-κB. In conclusion, dexmedetomidine inhibited the nuclear translocation and binding activity of activated NF-κB, thus reducing inflammatory cytokines.
Int. J. Mol. Sci.2014, 15(3), 4031-4048; doi:10.3390/ijms15034031 - published online 5 March 2014 Show/Hide Abstract
Abstract: Gastric cancer (GC) is among the most frequent types of cancer worldwide. Therefore, understanding the biology of GC tumorigenesis is important for appropriate diagnosis and patient surveillance. The miR-191/425 cluster has been reported to be overexpressed in various human cancers, but the tumorigenic role and clinical significance of miR-191/425 overexpression in gastric carcinogenesis is currently undefined. In this study, the expression of miR-191 and miR-425 in GC tissue and serum was assessed, and the relationship between miRNA expression and clinicopathological data was analyzed. We found that miR-191 and miR-425 were both significantly increased in human GC tissues relative to adjacent normal controls. In addition, miR-191 levels correlated with GC tumor stage and metastatic state. Furthermore, the level of serum miR-191 was significantly higher in the GC group than in the control group when using serum miR-16 as an endogenous control. Finally, inhibition of miR-191 or miR-425 in the GC cell lines HGC-27 not only reduced cell proliferation and cell cycle progression but also impaired cell migration and invasion. Taken together, our results revealed the oncogenic roles of miR-191 and miR-425 in gastric carcinogenesis, and indicated the potential use of serum miR-191 as a novel and stable biomarker for GC diagnosis.
Int. J. Mol. Sci.2014, 15(3), 4019-4030; doi:10.3390/ijms15034019 - published online 5 March 2014 Show/Hide Abstract
Abstract: The aim of this study was to determine the effect and mechanism of tamoxifen (TAM)-induced steatosis in vitro. HepG 2 (Human hepatocellular liver carcinoma cell line) cells were treated with different concentrations of TAM for 72 h. Steatosis of hepatocytes was determined after Oil Red O staining and measurement of triglyceride (TG) concentration. The expressions of genes in the TG homeostasis pathway, including sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα), fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), stearoyl-CoA desaturase (SCD), carnitine palmitoyltransferase 1 (CPT1) and microsomal triglyceride transfer protein (MTP), were examined using quantitative real-time PCR and Western blot analysis. Cell proliferation was examined using the cell counting kit-8 (CCK-8) assay. We found that hepatocytes treated with TAM had: (1) induced hepatocyte steatosis and increased hepatocyte TG; (2) upregulation of SREBP-1c, FAS, ACC, SCD and MTP mRNA expressions (300%, 600%, 70%, 130% and 160%, respectively); (3) corresponding upregulation of protein expression; and (4) no difference in HepG 2 cell proliferation. Our results suggest that TAM can induce hepatocyte steatosis in vitro and that the enhancement of fatty acid synthesis through the upregulations of SREBP-1c and its downstream target genes (FAS, ACC and SCD) may be the key mechanism of TAM-induced hepatocyte steatosis.