DNA damage-induced apoptosis suppressor (DDIAS) promotes the progression of lung cancer and hepatocellular carcinoma through the regulation of multiple pathways. We screened a chemical library for anticancer agent(s) capable of inhibiting DDIAS transcription. DGG-100629 was found to suppress lung cancer cell growth through the inhibition of DDIAS expression.
View Article and Find Full Text PDFDysregulation of mitochondrial homeostasis and accumulation of damaged mitochondria cause degenerative diseases such as age-related macular degeneration (AMD). We studied the effects of the intermediate cytofilament KRT8 (keratin 8) on mitochondrial homeostasis in relation to the morphology and function of mitochondria in retinal pigment epithelial cells under oxidative stress. When the mitochondria were damaged owing to oxidative stress, the damaged mitochondria were readily disposed of via mitophagy following mitochondrial fission.
View Article and Find Full Text PDFThe immunoproteasome (iP), an inducible proteasome variant harboring three immunosubunits, low molecular mass polypeptide-2 (LMP2), multicatalytic endopeptidase complex subunit-1, and low molecular mass polypeptide-7 (LMP7), is involved in multiple facets of inflammatory responses. We recently reported that YU102, a dual inhibitor of the iP subunit LMP2 and the constitutive proteasome catalytic subunit β1, ameliorates cognitive impairments in mouse models of Alzheimer's disease (AD) independently of amyloid deposits. To investigate whether inhibition of LMP2 is sufficient to improve the cognitive functions of AD mice, here we prepared 37 YU102 analogues and identified a potent LMP2 inhibitor DB-310 () (IC: 80.
View Article and Find Full Text PDFThe immunoproteasome (iP) is a variant of the constitutive proteasome (cP) that is abundantly expressed in immune cells which can also be induced in somatic cells by cytokines such as TNF-α or IFN-γ. Accumulating evidence support that the iP is closely linked to multiple facets of inflammatory response, eventually leading to the development of several iP inhibitors as potential therapeutic agents for autoimmune diseases. Recent studies also found that the iP is upregulated in reactive glial cells surrounding amyloid β (Aβ) deposits in brains of Alzheimer's disease (AD) patients, but the role it plays in the pathogenesis of AD remains unclear.
View Article and Find Full Text PDFRNase E is a component of the RNA degradosome complex and plays a key role in RNA degradation and maturation in RNase E-mediated target RNA degradation typically involves the RNA chaperone Hfq and requires small guide RNAs (sRNAs) acting as a seed by binding to short (7-12-bp) complementary regions in target RNA sequences. Here, using recombinantly expressed and purified proteins, site-directed mutagenesis, and RNA cleavage and protein cross-linking assays, we investigated Hfq-independent RNA decay by RNase E. Exploring its RNA substrate preferences in the absence of Hfq, we observed that RNase E preferentially cleaves AU-rich sites of single-stranded regions of RNA substrates that are annealed to an sRNA that contains a monophosphate at its 5'-end.
View Article and Find Full Text PDFCyclodextrins (CDs) have beneficial characteristics for drug delivery, including hydrophobic interior surfaces. Nanocarriers with -CD ligands have been prepared with simple surface modifications as drug delivery vehicles. In this study, we synthesized -CD derivatives on an Ag-embedded silica nanoparticle (NP) (SiO₂@Ag NP) structure to load and release doxorubicin (DOX).
View Article and Find Full Text PDFGraphene oxide (GO) is known to strongly bind single-stranded nucleic acids with fluorescence quenching near the GO surface. However, GO exhibits weak biocompatibility characteristics, such as low dispersibility in cell culture media and significant cytotoxicity. To improve dispersibility in cell culture media and cell viability of GO, we prepared nanosized GO (nGO) constructs and modified the nGO surface using polyethylene glycol (PEG-nGO).
View Article and Find Full Text PDFNon-small-cell lung cancer (NSCLC) is commonly caused by a mutation in the epidermal growth factor receptor (EGFR) and subsequent aberrant EGFR signaling with uncontrolled kinase activity. A deletion mutation in EGFR exon 19 is frequently observed in EGFR gene mutations. We designed a DNAzyme to suppress the expression of mutant EGFR by cleaving the mutant EGFR mRNA.
View Article and Find Full Text PDFContribution of autophagy and regulation of related proteins to the degeneration of retinal pigment epithelium (RPE) in age-related macular degeneration (AMD) remain unknown. We report that upregulation of KRT8 (keratin 8) as well as its phosphorylation are accompanied with autophagy and attenuated with the inhibition of autophagy in RPE cells under oxidative stress. KRT8 appears to have a dual role in RPE pathophysiology.
View Article and Find Full Text PDFExogenous nucleic acids induce an innate immune response in mammalian host cells through activation of the retinoic acid-inducible gene I (RIG-I). We evaluated RIG-I protein for RNA binding and ATPase stimulation with RNA ligands to investigate the correlation with the extent of immune response through RIG-I activation in cells. RIG-I protein favored blunt-ended, double-stranded RNA (dsRNA) ligands over sticky-ended dsRNA.
View Article and Find Full Text PDFJ Microbiol Biotechnol
October 2009
In an attempt to discover novel biomarker proteins in type 2 diabetes prognosis, we investigated the influence of hypoglycemic extracellular polysaccharides (EPS) obtained from the macrofungus Tremella fuciformis on the differential levels of plasma proteins in ob/ob mice using two-dimensional gel electrophoresis (2-DE). The 2-DE analysis demonstrated that 92 spots from about 900 visualized spots were differentially regulated, of which 40 spots were identified as principal diabetes-associated proteins. By comparing control with EPS-fed mice, we found that at least six proteins were significantly altered in ob/ob mice, including Apo A-I, IV, C-III, E, retinol-binding protein 4, and transferrin, and their levels were interestingly normalized after EPS treatment.
View Article and Find Full Text PDFThe endogenous ROS levels were increased during HepG2 apoptosis, whereas they were decreased during SK-N-SH apoptosis in response to capsaicin treatments. We used 2-DE-based proteomics to analyze the altered protein levels in both cells, with special attention on oxidative stress proteins before and after capsaicin treatments. The 2-DE analysis demonstrated that 23 proteins were increased and 26 proteins were decreased significantly (fold change>1.
View Article and Find Full Text PDFIn an attempt to search for novel biomarkers for monitoring diabetes prognosis, we examined the influence of the hypoglycemic fungal extracellular polysaccharides (EPS) on the differential change in pancreatic proteome and transcriptome in streptozotocin (STZ)-induced diabetic rats using 2-DE-based protein mapping and oligonucleotide microarray analysis. The 2-DE system separated more than 2000 individual spots, demonstrating that 34 proteins out of about 500 matched spots were differentially expressed. A total of 22 overexpressed and 12 underexpressed proteins in 2-DE map were observed (p<0.
View Article and Find Full Text PDFThree different polysaccharide-peptide complexes (PPC, named as Fr-I, Fr-II, and Fr-III) were produced by submerged mycelial culture of an entomopathogenic fungus Cordyceps sphecocephala, and their anticancer activities were investigated in human hepatocarcinoma (HepG2) and neuroblastoma (SK-N-SH) cells. The highest inhibitory effects of PPC on both HepG2 and SK-N-SH cells were achieved with Fr-I, whereas Fr-III with low molecular mass showed lower inhibition effects. Interestingly, the inhibitory effects of the three fractions were increased after protease digestion, suggesting that the inhibitory effects resulted mainly from the carbohydrate moiety, at least in the case of Fr-II and Fr-III, of PPC.
View Article and Find Full Text PDFJ Microbiol Biotechnol
January 2008
The 3T3-L1 cell line is a well-established and commonly used in vitro model to assess adipocyte differentiation. Over the course of several days, confluent 3T3-L1 cells can be converted to adipocytes in the presence of an adipogenic cocktail. In this study, the effects of chitosan oligosaccharides (CO) on adipocyte differentiation of 3T3-L1 cells were studied.
View Article and Find Full Text PDFIn the present study, optimum culture conditions for the production of extracellular polysaccharides (EPS) in submerged culture of an edible mushroom, Laetiporus sulphureus var. miniatus and their stimulatory effects on insulinoma cell (RINm5F) proliferation and insulin secretion were investigated. The maximum mycelial growth (4.
View Article and Find Full Text PDFIn the present study, we performed a differential proteomic analysis using 2-DE combined with MS to clarify the molecular mechanism for the suppressive effect of chitosan oligosaccharides (CO) during differentiation of adipocyte 3T3-L1. Cell differentiation was significantly inhibited by CO at the concentration of 4 mg/mL. Protein mapping of adipocyte homogenates by 2-DE revealed that numerous protein spots were differentially altered in response to CO treatment.
View Article and Find Full Text PDFDiabetic nephropathy remains a major cause of morbidity and mortality in the diabetic population and is the leading cause of end-stage renal failure. Despite current therapeutics including intensified glycemic control and blood pressure lowering agents, renal disease continues to progress relentlessly in diabetic patients, albeit at a lower rate. Since synthetic drugs for diabetes are known to have side effects, fungal mushrooms as a natural product come into preventing the development of diabetes.
View Article and Find Full Text PDFThe anti-diabetic activities of the exopolysaccharides (EPS) produced by submerged mycelial culture of two different mushrooms, Tremella fuciformis and Phellinus baumii, in ob/ob mice were investigated. All the animals were randomly divided into three groups with seven animals in each group: The control group received 0.9% NaCl solution; the diabetic groups were treated with EPS from T.
View Article and Find Full Text PDFPrevious studies about protein modulation with chemically induced models of diabetes in animals have yielded conflicting results, in that many investigators have reported different regulation patterns for the same proteins. Therefore, it is reasonable to determine biomarkers for prognosis and diagnosis of diabetes with time profiling for the candidate proteins. In this regard, we examined the influence of hypoglycemic fungal polysaccharides (EPS) on the time-dependent plasma protein alterations in streptozotocin-induced diabetic rats.
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