RNA binding protein Lin28A promotes osteocarcinoma cells progression by associating with the long noncoding RNA MALAT1

Objectives

To explore the effects of Lin28A on progression of osteocarcinoma (OS) cells.

Results

Lin28A mRNA and protein expressions were significantly increased in OS tissues compared with that in normal adjacent tissues. Expressions of Lin28A and long noncoding RNA MALAT1 were positively correlated. Patients with higher Lin28A expression had shorter overall survival. Moreover, Lin28A knockdown inhibited OS cells proliferation, migration, invasion and promoted cell apoptosis; Lin28A was found to harbor binding sites on MALAT1 sequences and associated with MALAT1, and increased MALAT1 stability and expression. Notably, the inhibition of Lin28A knockdown was attenuated or even reversed by MALAT1 overexpression.

Conclusions

RNA binding protein Lin28A could facilitate OS cells progression by associating with the long noncoding RNA MALAT1.

     

Toll-like receptor 9 agonists up-regulates the expression of cyclooxygenase-2 via activation of NF-κB in prostate cancer cells

CpG-oligonucleotides (CpG-ODNs), mimicking bacterial DNA, have recently been shown to stimulate prostate cancer invasion in vitro via Toll-like receptor 9 (TLR9). Since cyclooxygenase 2 (COX-2), frequently overexpressed in multiple tumor types including prostate cancer, is a causal factor for tumor development, invasion and metastasis, an interesting question is raised whether TLR9 regulates COX-2 expression in prostate cancer cells. To address this question, herein we examined COX-2 expression in PC-3 cells stimulated with different doses and time courses of CpG-ODNs. The regulatory role of NF-κB in TLR9-mediated COX-2 expression was also investigated. CpG-ODN was found to up-regulate the expression of COX-2 in PC-3 cells in a dose- and time-dependent manner, but have little impact on COX-1 expression. Moreover, CpG-ODN also promoted nuclear translocation and activation of NF-κB, which appeared to be required for COX-2 induction by CpG-ODN. Overall, TLR9 up-regulates COX-2 expression in prostate cancer cells, at least partially through the activation of NF-κB, which may be implicated in tumor invasion and metastasis.     

The dominant <Emphasis Type=Italic>Ulva</Emphasis> strain of the 2008 green algal bloom in the Yellow Sea was not detected in the coastal waters of Qingdao in the following winter

The region of Qingdao, China, experienced the world's largest green tide from May to July 2008. More than one million tons of fresh algal biomass of the green alga Ulva prolifera was harvested, while more was suspected to have sunk to the bottom. The original source of this seaweed was suspected to be from the south as revealed by satellite images. The floating biomass drifted with the water current northward and flourished in nearshore waters around Qingdao. However, direct biological evidence for “seed” source is lacking. It is still unclear whether this alga could survive the Qingdao local coastal environment and pose future danger of potential blooming. Systematic and seasonal sampling of waters in the intertidal zone at six collection sites along the Qingdao coast was conducted from December 2008 to April 2009. Forty-eight water samples were analyzed. From these, nine different morphotypes of Ulva were grown in the laboratory under standard temperature and light regimes. Growth of Ulva was observed in all water samples. However, molecular phylogenetic analyses revealed that the dominant U. prolifera strain of the 2008 bloom was absent in all the water-derived cultures during the sampling period. These results provide evidence that the dominant bloom-forming alga was unlikely able to survive the coastal waters (the minimal surface water temperature in February is 2°C) in winter conditions in Qingdao, even though all the sampling locations were heavily covered by this alga in June 2008.     

Quantum Attack-Resistent Certificateless Multi-Receiver Signcryption Scheme

The existing certificateless signcryption schemes were designed mainly based on the traditional public key cryptography, in which the security relies on the hard problems, such as factor decomposition and discrete logarithm. However, these problems will be easily solved by the quantum computing. So the existing certificateless signcryption schemes are vulnerable to the quantum attack. Multivariate public key cryptography (MPKC), which can resist the quantum attack, is one of the alternative solutions to guarantee the security of communications in the post-quantum age. Motivated by these concerns, we proposed a new construction of the certificateless multi-receiver signcryption scheme (CLMSC) based on MPKC. The new scheme inherits the security of MPKC, which can withstand the quantum attack. Multivariate quadratic polynomial operations, which have lower computation complexity than bilinear pairing operations, are employed in signcrypting a message for a certain number of receivers in our scheme. Security analysis shows that our scheme is a secure MPKC-based scheme. We proved its security under the hardness of the Multivariate Quadratic (MQ) problem and its unforgeability under the Isomorphism of Polynomials (IP) assumption in the random oracle model. The analysis results show that our scheme also has the security properties of non-repudiation, perfect forward secrecy, perfect backward secrecy and public verifiability. Compared with the existing schemes in terms of computation complexity and ciphertext length, our scheme is more efficient, which makes it suitable for terminals with low computation capacity like smart cards.     

Reaction of vascular adhesion protein-1 (VAP-1) with primary amines: mechanistic insights from isotope effects and quantitative structure-activity relationships

Human vascular adhesion protein-1 (VAP-1) is an endothelial copper-dependent amine oxidase involved in the recruitment and extravasation of leukocytes at sites of inflammation. VAP-1 is an important therapeutic target for several pathological conditions. We expressed soluble VAP-1 in HEK293 EBNA1 cells at levels suitable for detailed mechanistic studies with model substrates. Using the model substrate benzylamine, we analyzed the steady-state kinetic parameters of VAP-1 as a function of solution pH. We found two macroscopic pK(a) values that defined a bell-shaped plot of turnover number k(cat,app) as a function of pH, representing ionizable groups in the enzyme-substrate complex. The dependence of (k(cat)/K(m))(app) on pH revealed a single pK(a) value (～9) that we assigned to ionization of the amine group in free benzylamine substrate. A kinetic isotope effect (KIE) of 6 to 7.6 on (k(cat)/K(m))(app) over the pH range of 6 to 10 was observed with d(2)-benzylamine. Over the same pH range, the KIE on k(cat) was found to be close to unity. The unusual KIE values on (k(cat)/K(m))(app) were rationalized using a mechanistic scheme that includes the possibility of multiple isotopically sensitive steps. We also report the analysis of quantitative structure-activity relationships (QSAR) using para-substituted protiated and deuterated phenylethylamines. With phenylethylamines we observed a large KIE on k(cat,app) (8.01 ± 0.28 with phenylethylamine), indicating that C-H bond breakage is limiting for 2,4,5-trihydroxyphenylalanine quinone reduction. Poor correlations were observed between steady-state rate constants and QSAR parameters. We show the importance of combining KIE, QSAR, and structural studies to gain insight into the complexity of the VAP-1 steady-state mechanism.     

Performances of growth,photochemical efficiency,and stress tolerance of young sporophytes from seven populations of <Emphasis Type="Italic">Saccharina japonica</Emphasis> (Phaeophyta) under short-term heat stress

Temperature is one of the primary factors determining the geographic boundaries of the kelp Saccharina japonica. To compare the resistance of the offspring from different populations to heat stress, seven populations including Zhen-farmed population (ZFP), Daban-farmed population (DFP), Fujian-farmed population (FFP), Yanza-farmed population (YFP), Benniu-farmed population (BFP), Gaolv wild population (GWP) and Qingdao wild population (QWP) were chosen from different farms along the coasts of China where intensive farming of this species has been carried out. Offspring from these populations were obtained in the laboratory. The young sporophytes (1–3 cm) were subjected for 7 days to different temperature treatments of 10, 21, and 23°C, respectively. The results showed that blade elongation rates were retarded both at 21°C and 23°C in all the populations. The percentages of plants that developed white blade tip were more serious in ZFP, YFP, and DFP than in other populations. Offspring from QWP demonstrated the most outstanding capacity to resist high temperature, as judged by the results of the maximal photochemical efficiency (F _v/F _m), the potential photochemical efficiency (F _v/F _o), content of malondialdehyde and the regulation of antioxidant enzymatic systems. Next were the offspring from GWP and FFP. Offspring from ZFP had the least heat-stress tolerance. Three lines of evidence obtained in the present study further confirmed that QWP distributed at 36°N, the most southern distribution limit of this species in the North-Western coast of the Pacific, was the most ideal source as parental plants for breeding high-temperature-tolerant cultivar.     

Innate versus adaptive immunity in Candida albicans infection

Candida albicans is a common opportunistic pathogen, causing both superficial and systemic infection. Clinical observations indicate that mucocutaneous infections are commonly associated with defective cell-mediated immune responses, whereas systemic infection is more frequently seen in patients with deficiencies in neutrophil number or function. Analysis of mechanisms of host resistance against gastrointestinal and oral infection in mouse models has demonstrated an absolute dependence on CD4(+) T cells, although clearance also involves phagocytic cells. Both IL-12 and TNF-alpha appear to be important mediators, but mouse strain-dependent variations in susceptibility to infection may be related to T-cell enhancement of production of phagocytic cells by the bone marrow. In murine systemic infection, the role of innate and adaptive responses is less well defined. Studies in immunodeficient and T-cell-depleted mice suggest that clearance of the yeast may be predominantly a function of the innate response, whereas the adaptive response may either limit tissue damage or have the potential to cause immunopathology, depending on the host genetic context in which the infection takes place.     

Trans-Corneal Subretinal Injection in Mice and Its Effect on the Function and Morphology of the Retina

Purpose

To introduce a practical method of subretinal injection in mice and evaluate injection-induced retinal detachment (RD) and damage using a dynamic imaging system, electrophysiology, and histology.

Methods

After full dilation of a 2-month-old C57BL/6J mouse pupil, the cornea near the limbus was punctured with a 30 ½-gague disposable beveled needle. A 33 ½-gauge blunt needle was inserted through the corneal perforation into the anterior chamber, avoiding the lens before going deeper into the vitreous cavity, and penetrating the inner retina to reach the subretinal space. The mice were divided into four groups: in group 1, about 80–100% of the retina was filled with subretinally injected solution; in group 2, approximately 50–70% of the retina was filled with injected solution; in group 3, the procedures were stopped before solution injection; and non-injected eyes were used as the negative control in group 4. An optical coherence tomography (OCT) imaging system was used to monitor retinal reattachment during the first three days following the injections. Histological and functional changes were examined by light microscopy and electroretinography (ERG) at five weeks post-injection.

Results

After a short-term training, a 70% success rate with 50% or more coverage (i.e., retinal blebs occupied 50% or more retinal area and filled with the injected solution) with minimal injection-related damages can be achieved. Bleb formation was associated with retinal detachment (RD) between the neuroretina and the retinal pigment epithelium (RPE) layer. Partial RD could be observed at post-injection day 1, and by day 2 most of the retina had reattached. At 5 weeks post-injection, compared to uninjected control group 4, the b-wave amplitudes of ERG decreased 22% in group 1, 16% in group 2, and 7% in group 3; the b-wave amplitudes were statistically different between the uninjected group and the groups with either 50–70% or 80–100% coverage. The subretinal injection-induced RD reattached and became stable at five weeks post-injection, although some photoreceptor damage could still be observed in and around the injection sites, especially in 80–100% coverage group.

Conclusions

Trans-corneal subretinal injection is effective and practical, although subretinal injection-related damages can cause some morphological and functional loss.     

Statistical distributions of optimal global alignment scores of random protein sequences

Background  

The inference of homology from statistically significant sequence similarity is a central issue in sequence alignments. So far the statistical distribution function underlying the optimal global alignments has not been completely determined.     

Atomic Model of Rabbit Hemorrhagic Disease Virus by Cryo-Electron Microscopy and Crystallography

Rabbit hemorrhagic disease, first described in China in 1984, causes hemorrhagic necrosis of the liver. Its etiological agent, rabbit hemorrhagic disease virus (RHDV), belongs to the Lagovirus genus in the family Caliciviridae. The detailed molecular structure of any lagovirus capsid has yet to be determined. Here, we report a cryo-electron microscopic (cryoEM) reconstruction of wild-type RHDV at 6.5 Å resolution and the crystal structures of the shell (S) and protruding (P) domains of its major capsid protein, VP60, each at 2.0 Å resolution. From these data we built a complete atomic model of the RHDV capsid. VP60 has a conserved S domain and a specific P2 sub-domain that differs from those found in other caliciviruses. As seen in the shell portion of the RHDV cryoEM map, which was resolved to ∼5.5 Å, the N-terminal arm domain of VP60 folds back onto its cognate S domain. Sequence alignments of VP60 from six groups of RHDV isolates revealed seven regions of high variation that could be mapped onto the surface of the P2 sub-domain and suggested three putative pockets might be responsible for binding to histo-blood group antigens. A flexible loop in one of these regions was shown to interact with rabbit tissue cells and contains an important epitope for anti-RHDV antibody production. Our study provides a reliable, pseudo-atomic model of a Lagovirus and suggests a new candidate for an efficient vaccine that can be used to protect rabbits from RHDV infection.