Long noncoding RNA BC032469, a novel competing endogenous RNA, upregulates hTERT expression by sponging miR-1207-5p and promotes proliferation in gastric cancer

Long noncoding RNAs (lncRNAs) are emerging as new players in gene regulation and are associated with the development of cancers. To investigate the important role and mechanism of lncRNAs in the progression of gastric cancer, we screened lncRNAs in gastric cancer tissues and corresponding adjacent tissues, and assessed the effects on gastric cancer. Here, we report that BC032469, a novel lncRNA, expressed highly in gastric cancer tissues, and the upregulation was clinically associated with larger tumor size, poor differentiation and shorter survival of gastric cancer patients. Downregulation of BC032469 resulted in a significant inhibition of proliferation in vitro and in vivo. Mechanistically, BC032469 could directly bind to miR-1207-5p and effectively functioned as a sponge for miR-1207-5p to modulate the derepression of hTERT. Thus, BC032469 may function as a ceRNA to impair miR-1207-5p-dependent hTERT downregulation, suggesting that it may be clinically valuable as a poor prognostic biomarker of gastric cancer.

Low molecular weight polyethylenimines linked by β-cyclodextrin for gene transfer into the nervous system

BACKGROUND

Polyethylenimines (PEIs) with high molecular weights are effective nonviral gene delivery vectors. However, the in vivo use of these PEIs can be hampered by their cellular toxicity. In the present study we developed and tested a new PEI polymer synthesized by linking less toxic, low molecular weight (MW) PEIs with a commonly used, biocompatible drug carrier, beta-cyclodextrin (CyD).

METHODS AND RESULTS

The terminal CyD hydroxyl groups were activated by 1,1'-carbonyldiimidazole. Each activated CyD then linked two branched PEI molecules with MW of 600 Da to form a CyD-containing polymer with MW of 61 kDa, in which CyD served as a part of the backbone. The PEI-CyD polymer developed was soluble in water and biodegradable. In cell viability assays with sensitive neurons, the polymer performed similarly to low-MW PEIs and displayed much lower cellular cytotoxicity compared to PEI 25 kDa. The gene delivery efficiency of the polymer was comparable to, and at higher polymer/DNA ratios even higher than, that offered by PEI 25 kDa in neural cells. Attractively, intrathecal injection of plasmid DNA complexed by the polymer into the rat spinal cord provided levels of gene expression close to that offered by PEI 25 kDa.

CONCLUSIONS

The polymer reported in the current study displayed improved biocompatibility over non-degradable PEI 25 kDa and mediated gene transfection in cultured neurons and in the central nervous system effectively. The new polymer would be worth exploring further as an in vivo delivery system of therapeutic genetic materials for gene therapy of neurological disorders.

Functional domains of the nuclear receptor hepatocyte nuclear factor 4

The hepatocyte nuclear factor 4 (HNF-4) is a member of the nuclear receptor superfamily and participates in the regulation of several genes involved in diverse metabolic pathways and developmental processes. To date, the functional domains of this nuclear receptor have not been identified, and it is not known whether its transcriptional activity is regulated by a ligand or other signals. In this report, we show that HNF-4 contains two transactivation domains, designated AF-1 and AF-2, which activate transcription in a cell type-independent manner. AF-1 consists of the extreme N-terminal 24 amino acids and functions as a constitutive autonomous activator of transcription. This short transactivator belongs to the class of acidic activators, and it is predicted to adopt an amphipathic alpha-helical structure. In contrast, the AF-2 transactivator is complex, spanning the 128-366 region of HNF-4, and it cannot be further dissected without impairing activity. The 360-366 region of HNF-4 contains a motif that is highly conserved among transcriptionally active nuclear receptors, and it is essential for AF-2 activity, but it is not necessary for dimerization and DNA binding of HNF-4. Thus, HNF-4 deletion mutants lacking the 361-465 region bind efficiently to DNA as homo- and heterodimers and behave as dominant negative mutants. Remarkably, the full transactivation potential of AF-2 is inhibited by the region spanning residues 371-465 (region F). The inhibitory effect of region F on the HNF-4 AF-2 activity is a unique feature among members of the nuclear receptor superfamily, and we propose that it defines a distinct regulatory mechanism of transcriptional activation by HNF-4.

Inhibition of the amygdala and hippocampal calcium/calmodulin-dependent protein kinase II attenuates the dependence and relapse to morphine differently in rats

Learning and memory have been suggested to play an important role in the development of opiate addiction. Based on the recent finding that calcium/calmodulin protein kinase II (CaMKII) is essential in learning and memory processes, the present study was performed to examine whether inhibition of hippocampal and amygdala CaMKII prevents the dependence and relapse to morphine. The results showed that inhibition of CaMKII by microinjection of specific inhibitors KN-62 into hippocampus decreased the morphine withdrawal syndromes induced by opiate antagonist naloxone. In contrast, inhibition of CaMKII in amygdala failed to do so. Microinjection of KN-62 into both hippocampus and amygdala suppressed the development of formation and reactivation of morphine conditioned place preference (CPP). However, inhibition of CaMKII in amygdala, but not in hippocampus, could attenuate the maintenance of morphine CPP. These results suggest that hippocampal CaMKII is critically involved in the development of morphine physical and psychological dependence, and amygdala CaMKII is some different from hippocampal CaMKII in regulating the dependence and relapse to opiates. Inhibition of this kinase may have some therapeutic benefit in the treatment of opiate dependence and relapse.

Determination of quercetin and kaempferol in human urine after orally administrated tablet of ginkgo biloba extract by HPLC

A sensitive, simple and accurate method was developed for determination of quercetin and kaempferol in human urine by reversed phase high performance liquid chromatography. The urine samples were analyzed on C18 column. Quercetin and kaempferol were analyzed simultaneously with good separation. UV detector was set at 380 nm. There was a linear relationship between chromatographic area of analytes and concentration of analytes over the concentration range 1.638-81.90 and 1.872-93.60 ng/ml for quercetin and kaempferol, respectively. The recovery of the assay was 99.7+/-6.2 and 97.4+/-7.2% for quercetin and kaempferol, respectively. The within-day and between-day coefficients of variation were less than 9.7 and 16.5% (RSD), respectively. The limit of detection was 1.0 ng/ml for quercetin and 1.1 ng/ml for kaempferol. The limit of quantitation was 1.61+/-0.11 ng/ml (n=5) for quercetin and 1.85+/-0.11 ng/ml (n=5) for kaempferol. The method developed has been applied to determine quercetin and kaempferol after orally administrated tablet of Ginkgo biloba extract in human urine.

Immunosuppressive effect of the gut microbiome altered by high-dose tacrolimus in mice

The alterations induced in gut microbiota by tacrolimus may affect immune function and organ transplantation. Mice were treated with high-dose tacrolimus for 14 days. The fecal microbiota were analyzed by pyrosequencing the 16S rRNA genes, and the effect on metabolism was predicted using the sequence data. The subgroups of T cells in the serum, gut-associated lymphoid tissue, and draining lymph nodes were determined by flow cytometry. Tacrolimus treatment significantly altered the relative abundance of Allobaculum, Bacteroides, and Lactobacillus and CD4⁺ CD25^hi FoxP3⁺ regulatory T cells in the colonic mucosa and the circulation. These were significantly increased after either tacrolimus treatment or treatment by fecal microbiota transfer from tacrolimus-treated donors. Further, treatment with low-dose tacrolimus plus fecal microbiota transfer from high-dose tacrolimus-altered mice increased skin allograft survival rate in a skin transplantation model. Thus, high-dose tacrolimus alters the compositions and taxa of the gut microbiota. Administration of these conditioned gut microbiota plus low-dose tacrolimus resulted in regulation of colonic and systemic immune responses and an increased allograft survival rate. This study demonstrated a new strategy for controlling allograft rejection by combining an immunosuppressive agent with gut microbiome transplantation.

Comparative analysis of the bacterial community compositions of the shrimp intestine, surrounding water and sediment

AIMS

To reveal the relationship of the bacterial communities in shrimp intestine and surrounding environments.

METHODS AND RESULTS

We examined bacterial communities in the intestine of pacific white shrimp, Litopenaeus vannamei, the surrounding water and sediment by high-throughput sequencing analysis. Sequences were clustered into operational taxonomic units (OTUs) at 97% similarity levels, which ranged from 4956 to 5976 in each sample. All OTUs were affiliated with at least 64 phyla. The 10 most abundant phyla were Proteobacteria, Cyanobacteria, Bacteroidetes, Chloroflexi, Firmicutes, Acidobacteria, Actinobacteria, Planctomycetes, Gemmatimonadetes and Verrucomicrobia. The relationship of bacterial communities in the intestine and the surroundings was also investigated. A total of 1395 OTUs shared in the three habitats, accounting for 80, 65 and 77% in the intestine, the surrounding water and sediment respectively. There were 352, 891, 833 unique OTUs in intestine, surrounding water and sediment. Welch's t-test analysis showed that the abundances of some taxa were significantly different between the shrimp intestine and surroundings. Unweighted pair-group method with arithmetic mean analysis revealed that there was a generally similar bacterial community composition in three environments.

CONCLUSIONS

These results showed that the bacterial compositions are mostly the same in shrimp intestine, water and sediment, but with different relative abundances of the bacterial communities.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provided valuable findings on the relationship of the bacterial communities in shrimp intestine, the surrounding water and sediment, which can expand our knowledge of the broad trend on bacterial community in shrimp cultural ecosystems.

High-performance liquid chromatography separation and quantitation of ofloxacin enantiomers in rat microsomes

A sensitive, simple and accurate method for determination of enantiomers of ofloxacin in microsomal incubates was developed by chiral ligand-exchange RP-HPLC with fluorescence detection to examine stereoselective metabolism of ofloxacin in the glucuronidation process. The C18 stationary phase was used as analytical column. The solution of chiral mobile phase additive was made up of 6 mM L-phenylalamine mixed with 3 mM CuSO4 in water. Mobile phase consisted of the solution of chiral mobile phase additive-methanol (86:14). The fluorescence detector was operated at lambda(ex) 330 nm and lambda(em) 505 nm. The flow-rate of mobile phase was set at 1.0 ml/min. The achiral ODS column offers good separation of the two enantiomers in less than 25 min. The recovery of the assay was 97.9+/-6.1% (n=10) for S-ofloxacin and 99.6+/-6.0% (n = 10) for R-ofloxacin. The method provides a high sensitivity and good precision (RSD<10%). The LOD was 0.6 microM for both enantiomers and the LOQ was 5.70+/-0.45 microM (n=8) for S-ofloxacin and 5.66+/-0.47 microM (n=8) for R-ofloxacin. The standard curves showed excellent linearity over the concentration range 5.5-2078 microM for S-(-)-ofloxacin and R-(+)-ofloxacin. The enantioselective method developed has been applied to determine the stereoselectivity of glucuronidation metabolism of ofloxacin optical isomers in rat liver microsomes.

Targeting STING attenuates ROS induced intervertebral disc degeneration

OBJECTIVE

DNA damage induced by ROS is considered one of the main causes of nucleus pulposus (NP) cells degeneration during the progression of intervertebral disc degeneration (IVDD). cGAS-STING pathway acts as DNA-sensing mechanism for monitoring DNA damage. Recent studies have proved that cGAS-STING contributes to the development of various diseases by inducing inflammation, senescence, and apoptosis. This work explored the role of STING, the main effector of cGAS-STING signaling pathway, in NP degeneration.

METHOD

Immunohistochemistry was conducted to measure STING protein levels in the nucleus pulposus tissues from human and puncture-induced IVDD rat models. TBHP induces degeneration of nucleus pulposus cells in vitro. For in vivo experiments, lv-NC or lv-STING were injected into the central intervertebral disc space. The degeneration level of IVDD was assessed by MRI, X-ray, HE, and Safranin O staining.

RESULTS

We found that the expression of STING was upregulated in human and rat degenerated NP tissue as well as in TBHP-treated NP cells. Overexpression of STING promoted the degradation of extracellular matrix; it also promoted apoptosis and senescence of TBHP-treated and untreated NP cells. Knock-down of STING significantly reversed these effects. Mechanistically, STING activated IRF3, whereas blockage of IRF3 attenuated STING-induced apoptosis, senescence and ECM degradation. In vivo experiments revealed that STING knock-down alleviated puncture-induced IVDD development.

CONCLUSION

STING promotes IVDD progress via IRF3, while suppression of STING may be a promising treatment for IVDD.

Immobilisation on polystyrene of diazirine derivatives of mono- and disaccharides: biological activities of modified surfaces

The potential of surface glycoengineering for biomaterials and biosensors originates from the importance of carbohydrate-protein interactions in biological systems. The strategy employed here utilises carbene generated by illumination of diazirine to achieve covalent bonding of carbohydrates. Here, we describe the synthesis of an aryl diazirine containing a disaccharide (lactose). Surface analysis techniques [X-ray photoelectron spectroscopy (XPS) and time of flight secondary ion mass spectroscopy (ToF-SIMS)] demonstrate its successful surface immobilisation on polystyrene (PS). Results are compared to those previously obtained with an aryl diazirine containing a monosaccharide (galactose). The biological activity of galactose- or lactose-modified PS samples is studied using rat hepatocytes, Allo A lectin and solid-phase semi-synthesis with alpha-2,6-sialyltransferase. Allo A shows some binding to galactose-modified PS but none to lactose-modified surfaces. Similar results are obtained with rat hepatocytes. In contrast, sialylation of lactose-modified PS is achieved but not with galactose-modified surfaces. The different responses indicate that the biological activity depends not only on the carbohydrate per se but also on the structure and length of the spacer.

IL-33 Receptor (ST2) Signalling is Important for Regulation of Th2-Mediated Airway Inflammation in a Murine Model of Acute Respiratory Syncytial Virus Infection

T1/ST2, an orphan receptor with homology with the interleukin (IL)-1 receptor family, is the ligand-binding component of the receptor for the cytokine IL-33, a newly identified cytokine known to amplify the Th2 cell-dominant immune responses. The function of IL-33/ST2 signalling during respiratory syncytial virus (RSV) infection is not fully known. In this study, following intranasal infection with RSV, BALB/c mice showed a marked increase in the production of IL-33, with an elevated expression of ST2 mRNA as well as a massive infiltration of CD45(+) ST2(+) cells in the lungs, suggesting that during the early phase of RSV infection, IL-33 target cells which express ST2 on cell surface, may play a critical role for the development of RSV-induced airway inflammation. Indeed, blocking ST2 signalling using anti-ST2 monoclonal antibody diminished not only RSV-induced eosinophil recruitment, but also the amounts of Th2-associated cytokines, particularly IL-13, and Th17-type cytokine IL-17A in the lungs of infected mice. However, anti-ST2 antibody treatment did not affect the production of Th1-type cytokine IFN-γ as well as pulmonary viral growth and clearance. These results indicate that IL-33/ST2 signalling is involved in RSV-induced, Th2-associated airway inflammation but not protective immunity.

Stable and unstable transgene integration sites in the human genome: extinction of the Green Fluorescent Protein transgene in K562 cells

In gene transfer experiments including gene therapy studies, expression of the integrated transgenes in host cells often declines with time. The molecular basis of this phenomenon is not clearly understood. We have used the Green Fluorescent Protein (GFP) gene as both a selectable marker and a reporter to study long-term transgene integration and expression in K562 cells. Cells transfected with plasmids containing the GFP gene coupled to the HS2 or HS3 enhancer of the human beta-globin Locus Control Region (LCR) or the cytomegalovirus (CMV) enhancer were sorted by either fluorescence-activated-cell-sorting (FACS) alone or FACS combined with drug selection based on a co-integrated drug resistance gene. The two groups of selected cells were subsequently cultured for long periods up to 250 cell generations. Comparison of long-term GFP transgene integration and expression in these two groups of cells revealed that the K562 genome contains two types of transgene integration sites: i) abundant unstable sites that permit transcription but not long-term integration of the transgenes and thus eliminate the transgenes in 60-250 cell generations and ii) rare stable sites that permit both efficient transcription and long-term stable integration of the transgenes for at least 200 cell generations. Our results indicate that extinction of GFP expression with time is due at least in part to elimination of the gene from the host genome and not entirely to transcriptional silencing of the gene. However, long-term, stable expression of the transgene can be achieved in cells containing the transgene integrated into the rare, stable host sites.

Intravitreal pharmacokinetics of liposome-encapsulated amikacin in a rabbit model

BACKGROUND

Intravitreal injection of antibiotics has become a standard therapy for bacterial endophthalmitis. The duration of effective antimicrobial levels in the vitreous after single injection, however, may not be long enough to get optimal response. The authors prepared liposome-encapsulated amikacin for prolonging the duration of intravitreal therapeutic concentrations and investigated the intravitreal pharmacokinetics of the liposomes and amikacin in phosphate buffer solution (PBS) as control.

METHODS

The liposome-encapsulated amikacin was prepared by reverse-phase evaporation method. The intravitreal pharmacokinetics of the liposomes was compared with amikacin in PBS by fluorescence polarization immunoassay. Albino rabbits were randomly distributed into 12 groups. Rabbits in groups 1 to 6 and in groups I to VI (control groups) received an intravitreal injection of the liposome-encapsulated amikacin and amikacin in PBS, respectively.

RESULTS

The encapsulation rate of amikacin was 91%. The time of 50% spontaneous degradation (half-life) of the liposomes in PBS (38 degrees C, pH 7.4) was 47.6 days, and the time of 50% release (half-life) of the drug from the liposomes in PBS was 84.8 hours. The vitreous amikacin concentrations in groups 1 to 6 were significantly greater (P < 0.05) than those in control groups I to VI in every time interval, except in groups 1 to 3 at 1 hour after injection. The difference was particularly obvious in the endophthalmitis groups. The clearance of encapsulated amikacin in vitreous appeared to be related to the state of blood-ocular barrier and to the structural integrity of vitreous. The distribution, the absorption, and the elimination of encapsulated amikacin in vitreous showed the first-order kinetics.

CONCLUSION

The liposome-encapsulated amikacin prolonged half-life of the drug in vitreous. The results of the pharmacokinetic analysis suggested that in endophthalmitis, especially in severe cases, the liposomes may be preferable to conventional preparation.

Volume of intracranial structures on three-dimensional ultrasound in fetuses with congenital heart disease

OBJECTIVE

To investigate the volume of intracranial structures in fetuses with congenital heart disease (CHD).

METHODS

Total intracranial volume, frontal lobes volume, thalamus volume and cerebellar volume were prospectively evaluated and compared in 73 fetuses with CHD and 168 normal fetuses using three-dimensional ultrasound combined with post-processing software at 20 + 0 to 36 + 6 weeks of gestation. Multiple regression analyses were performed to identify risk factors for reduced volume of intracranial structures.

RESULTS

From the 28th week of gestation onwards, total brain volumes and those of specific structures became progressively smaller in fetuses with CHD relative to those in controls (P < 0.05). The decrease was largest in frontal lobes volume, followed by total intracranial volume and cerebellar volume, and the smallest decrease was in thalamus volume (P < 0.05). Multivariable analysis showed that the diagnostic category (P < 0.001) was independently associated with smaller brain volumes in fetuses with CHD. The largest differences from controls occurred in hypoplastic left heart syndrome (HLHS), followed by aortic hypoplasia, transposition of the great arteries (TGA) and tetralogy of Fallot (TOF).

CONCLUSIONS

The volume of intracranial structures is smaller in fetuses with CHD, particularly in those with HLHS, aortic hypoplasia or TGA. This study highlights the need for routine brain screening and early intervention to improve neurodevelopmental outcomes in fetuses with CHD.

Controlled release of levonorgestrel from biodegradable poly(D,L-lactide-co-glycolide) microspheres: in vitro and in vivo studies

Poly(D,L-lactide-co-glycolide) (PLG) biodegradable microspheres containing a contraceptive drug, levonorgestrel (LNG), were prepared using both the solvent evaporation method and a modified solvent extraction-evaporation method. The microspheres prepared with the solvent evaporation process had porous surfaces with low product yields and poor encapsulation efficiencies. On the other hand, the microspheres prepared using the modified solvent extraction-evaporation method were nonporous with encapsulation efficiencies close to 100%. In vitro drug release showed the nonporous microspheres had a lower initial burst and a slightly prolonged duration of release than those porous microspheres. In vivo release kinetics of the low burst microspheres were determined by measuring LNG plasma levels after a single intramuscular injection to female rats. At a LNG dose of 41.1 mg/kg, average plasma LNG levels were 6-10 ng/ml in the first 24 h and subsequently remained above 1 ng/ml until 126 days. The duration above the minimum effective LNG plasma level of 0.2 ng/ml was 168 days. By comparison, a similar dose of LNG microcrystals used as control produced a much higher plasma level of 15-21 ng/ml in the first day followed by a fast and continuous decline of LNG levels with a duration of only about 35 days.

Expression of functional soluble forms of human beta-1, 4-galactosyltransferase I, alpha-2,6-sialyltransferase, and alpha-1, 3-fucosyltransferase VI in the methylotrophic yeast Pichia pastoris

The cDNAs encoding soluble forms of human beta-1, 4-galactosyltransferase I (EC 2.4.1.22), alpha-2,6-sialyltransferase (EC 2.4.99.1), and alpha-1,3-fucosyltransferase VI (EC 2.4.1.65), respectively, have been expressed in the methylotrophic yeast Pichia pastoris. The vector pPIC9 was used, which contains the N-terminal signal sequence of Saccharomyces cerevisiae alpha-factor to allow entry into the secretory pathway. The recombinant enzymes had similar kinetic properties as their native counterparts. Their identity was confirmed by Western blotting. Recombinant enzymes may be used for in vitro synthesis of oligosaccharides.

Charge and Spin Order Dichotomy in NdNiO_{2} Driven by the Capping Layer

Superconductivity in infinite-layer nickelates holds exciting analogies with that of cuprates, with similar structures and 3d-electron count. Using resonant inelastic x-ray scattering, we studied electronic and magnetic excitations and charge density correlations in Nd_{1-x}Sr_{x}NiO_{2} thin films with and without an SrTiO_{3} capping layer. We observe dispersing magnons only in the capped samples, progressively dampened at higher doping. We detect an elastic resonant scattering peak in the uncapped x=0 compound at wave vector (∼⅓,0), remindful of the charge order signal in hole doped cuprates. The peak weakens at x=0.05 and disappears in the superconducting x=0.20 film. The role of the capping on the electronic reconstruction far from the interface remains to be understood.

Quantitative regioselectivity of glucuronidation of quercetin by recombinant UDP-glucuronosyltransferases 1A9 and 1A3 using enzymatic kinetic parameters

Quercetin has been suggested to exert its pharmacological effects, at least in part, via its metabolites, such as glucuronides. Quantitative regioselectivity analyses are important to understand the contributions of UDP-glucuronosyltransferases (UGTs) to the pharmacological activity of quercetin. The present work obtained active UGT1A9 and UGT1A3 enzymes with a Bac-to-Bac expression system, and quercetin was metabolized by each of them to four monoglucuronides (7-, 3-, 4'- and 3'-glucuronide). Enzymatic kinetic parameters of each glucuronide were calculated to elucidate quantitatively UGT1A9's and UGT1A3's regioselectivities for quercetin. UGT1A3's highest glucuronidation efficiency was observed for the 3'-glucuronide, then the 3-, 4'- and 7-glucuronide. The catalytic efficiency order for UGT1A9 was 3->7->3'->4'-glucuronide.